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i 

1 1 



II 



U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 151. 



A STUDY OF THE GASES OF 
E.MMENTAL CHEESE. 

" OCT IG V3u' 



WILLIAM MANSFIELD CLARK, Pk. D., 
Chemist, Dairy Division. 



WASHINGTON! 

GOVERNMENT PRINTING OFFICE. 

1912. 



THE BUREAU OF ANIMAL INDUSTRT. 



Chief: A. D. Melvin. 

As9uUmi Chief: A. M. Farringtok. 

Chief Clerh: Charles 0. Carroll. 

Animal HuBhandry IHvisum: George M. Rommel, chief. 

Biocheniic Division: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. "* 

Field Inspection Division: R. A. Ramsat, chief. 

Meat Inspection Division: Rice P. Stbddom, chief. 

Pathological Division: John R. Mohler, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: E. C. Schroeder, superintendent. 

Editor: James M. Pickens. 

DAIRY division. 

B. H. Rawl, Chief 

Helmer Rabild, in charge of Dairy Farming Investigations. 

S. C. Thompson, in charge of Dairy Manufacturing Investigations. 

L. A. Rogers, in charge of Research Laboratories, 

Ernest Kellt, in charge of Market Milk Investigations. 

Robert McAdam, in charge of Renovated Butter Inspection. 

2 



additional copies of this pablicatioil 
XI. may be i>rocared from the Bupb]unteni>- 
Mxn or DocuMENiB, Qoyenimeat PrlnttDS 
Office, Washington, D. C, at 6 cents per copy 



LETTER OF TRANSMITTAL. 



U. S. Depabtment of Ageicultuke, 

BtTBEAu OP Animal Industey, 
WasUngUm, D. C, AprU £S, 1912. 

Sib: I have the honor to transmit, and to recommend for publi- 
cation in the bulletin series of the bureau, the accompanying manu- 
script entitled '*A Study of the Gases of Emmental Cheese," by Dr. 
William Mansfield dark, chemist in the Dairy Division. 

The so-called ''eyes" in Swiss cheese are, as is well known, its most 
prominent characteristic, and its commercial value is largely depend- 
ent upon the proper size and spacing of these eyes. Furthermore, 
much depreciation in the value of this popular variety of cheese, in 
both the domestic and foreign kinds, is known to exist because of 
defects in eye formation. The experimental work herein described 
concerns the chemical contents of these eyes, and although consider- 
able work has been done in Europe Mdth the object of discovering the 
cause of eye formation, there has hitherto been no investigation made 
of the gases which are immediately concerned in the process. Dr. 
Clark's studies are therefore calculated to be of value to the scientific 
as well as the practical side of the industry. 

Respectfully, 

A. D. Melvin, 

Chief of Bureau, 

Hon. James Wilson, 

Secretary of Agriculture. 

3 



265044 



CONTENTS. 



Page. 

Introduction 7 

Description of apparatus and methods of collecting the gases 9 

Method 1 9 

Method II 10 

Method of analysis 11 

Discussion of the analyses 12 

Absorption of oxygen 18 

The permeability of cheese to gases 20 

Nitrogen dissolved in curd 24 

Does nitrogen originate in situ? 25 

Relation between carbon dioxid and volatile acids 26 

Summary 31 

References to literature 32 

5 



ILLUSTRATIONS. 



Pass. 

Fig . 1 . Apparatus for collectmg gas from the eyes of Swiss or Emmental cheese . . 8 

2. Apparatus for pumping gas from cheese 10 

3. Apparatus for studying the absorption of oxygen by cheese 14 

4. Device for ascertaining permeability of cheese to gasee . . ^ 20 

6. Apparatus for determining amount of nitrogen in curd 24 

m 

6 



A STUDY OF THE GASES OF EMMENTAL CHEESE. 



INTRODUCTION, 

The "eyes" of Swiss or Emmental cheese are its most strikiiig 
characteristic. Their formation is a fascinating subject to the bio- 
logical chemist, because of a supposed localization of reactions gen- 
erating considerable quantities of gas, and because of the produc- 
tion of a plasticity among the colloids of the cheese, which makes 
possible the peculiar mold of the cavities. 

To the cheese maker the formation of the "eyes" is a matter of 
great importance, since their size and proper spacing determine in 
large measure the commercial value of the cheese. In certain dis- 
tricts of Wisconsin visited by the writer the dealers rely almost 
entirely upon these features, and, shortly after the eyes have reached 
their proper development, relieve the maker of further care. The 
American makers of Swiss cheese are, therefore, unable to attend 
to their cheeses in that meUow old age upon which so much of the 
fine flavor of a true Emmental cheese depends. However much this 
quick marketing is to be deprecated, the fact remains that it raises 
the relative importance of the eye formation and adds significance 
to whatever knowledge can be gained concerning the process. 

Some years ago Bachler,* ** cited by Jensen," estimated that 26 
per cent of the cheeses made in Switzerland were considerably reduced 
in value because of imperfect eye formation. How far this enormous 
loss has been lessened in recent years as a result of scientifically con- 
trolled manufacture can not be said, but in this country, where large 
nimibers of Swiss are still using the antiquated methods of their fore- 
fathers, Bachler's estimate is probably not too high. The wide dif- 
ference in market price between domestic and imported Swiss cheese 
bears out this statement. 

Considerable work has been done in Europe in the effort to uncover 
the cause of eye formation, and, through the labors particularly of 

o The lefeLCDoe flgores relate to the list of referenoes to literature at end of buUethi. 

7 



8 STUDY OT OASES OF EUUETTTAI. CHEESB. 

Von Freudenreicli and Jensen, a weLl-founded theory has been proposed 
which wiU be discussed later. No one, howeTer, has made a study of 
the gases which are themselves the immedi&te cause of the eye forma- 
tioD, and it was with the hope that such a study might furnish valu- 
able data that the nesearch herein described was undertaken. IS 
nothing more is demonstrated than the composition of the gas in 

Y7 



/^ 



Fio. I.— Apparatus (or odlectiiig gfta In 



the eyes, this alone justifies the work, for the extensire researches on 
the eye formation in Knimental cheese have led to but one codclu- 
mob that can be called positive, and that is that a final explanation 
will be reached only when every phase of the subject has been sub- 
mitted to exact quantitative study. 



APPABATUS AND METHODS. 9 

DSSCRIPTION OF APPARATUS AND METHODS 07 COLLBCTINO THE 

GASES. 

The collection of the gas in the eyes by cutting the cheese under a 
bell jar filled with water, as was donewith Edam cheese by Boekhout 
and Ott de Viies,' is a simple and valuable method, but one which 
is hardly to be called accurate, owing to the high solubility of certain 
gases in water. In place of such a method an apparatus was devised 
for collecting the gas over mercury. This is shown in figure 1, the 
procedure being as follows: 

METHOD I. 

The glass cyhnder A is forced a short distance into the body of 
the cheese until it is firmly held. It is then clamped in position. 
Around the outside the cheese is cut away sufficiently to leave a 
channel into which mercury moistened with mercuric chlorid solution 
is poured. This forms a seal preventing entrance of air. The head 
of the shaft B is now resting on the surface of the cheese. Through 
its capillary mercury is run into the cylinder, displacing the air until 
it finally runs out of the side arm D and up through the annular 
space between the shaft and the shoulder of the cylinder. The short 
length of thick rubber tubing at E is then very tightly boimd with a 
rubber band, leaving mercury in the small cup above, and thus 
effectually dosing this opening against the entrance of air. When 
the cylinder and side arm are thus completely filled with mercury, a 
receptade filled with mercury is brought over the end of the side 
arm (in a mercury trough, of course) and serves to retain the col- 
lected gas until the time of the analysis. After these preparations 
the shaft is pushed down into the cheese. When it pimctures an 
eye this can readily be felt. Since the head of the shaft is larger 
than the shank, there is left an annular space for the escape of the 
gas. This gas is displaced from the eye partially by the mercury of 
the cylinder, which finds its way to the lower level, but more largely 
by the mercury which runs in through the capillary in the shaft. The 
exit of this is prevented from becoming dogged with cheese by care- 
fully blowing it out just bdiind the head, as shown in the diagram. 
When the gas is displaced from the eye it is displaced from the 
cylinder into the receiver by continuing to run in mercury through 
the shaft from the reservoir C. Between this reservoir and the shaft 
is placed a bulb which prevents the mercury from sweeping in bub- 
bles of air. 

In the samples of gas collected with this apparatus seldom was more 
than a trace of oxygen found. This in itself shows that the gas was 
obtained without contamination by air. 

42208^— BuU. 151—12 2 



10 



BTUDY OF GASE8 OF EMMEKTAL CHEESE. 




METHOD U. 

For the collection of gas from ''pinholes'' the foregoing apparatus 

was of little use except in one instance to be mentioned later. To 

collect the gas from this form of hole, as well as the gas in the body 

of the cheese, the apparatus shown in figure 2 was used, as follows: 

Samples of cheese taken with a trier were introduced into the 

glass cylinder A. The rubber 
stopper at B, attached to the 
mercury vacuum pump with or 
without the intermediate connec- 
tion C, was forced in securely and 
protected from leakage by the 
mercury seal. Upon raising the 
leveling bulb D the cheese was 
flooded with mercury and the sur- 
rounding air was forced over into 
the pump until the mercury stood 
at the stopcock E. To prevent 
bubbles of air being trapped under 
the cheese the lower ends of the 
plugs were sharply beveled. Bub- 
bles of air of course adhered to the 
rough surface of the cheese and its 
smaller exposed cavities. This 
error is inherent in the method, 
but was reduced by suddenly drop- 
ping theleveling bulb with the stop- 
cockE closed, and then driving the 
air, which had expanded into the 
vacuum, past the open stopcock. 
The glass tube with its trap 
which connects A with the level- 
ing bulb was made sufficiently 
long so that D might be lowered 
the barometric distance below A, 
and thus leave the cheese exposed 
to a fairly high vacuum even be- 
fore the pumping commenced. After exhausting the pump up to 
E this cock was opened, and the gas pumped from the cheese and 
delivered into a receiver. 

The merciury pump used in this as in other operations to be de- 
scribed later was Antropoff's modification of the Topler. A full 
description of the pump and its appurtenances will appear in the 
account of another investigation. 




Fio. 2.— App&ratu3 for pumping gas from cheese. 






METHOD OF ANALYSIS. 



11 



IKEXHOD OF ANALYSIS. 

The gas was analyzed with a special set of burettes and pipettes 
designed for the analysis of small quantities of gas produced by 
bacteria. A few of the first analyses were made with a burette spe- 
cially designed for volumes as low as 0.5 c. c. In all the analyses 
the confining liquid was mercury, and use was made of a device for 
extremely accurate separation of gas from absorbent. 

Thirty-three per cent potassium hydroxid solution, in quantities 
appropriate for the volume of gas analyzed, served as absorbent for 
carbon dioxid. Hydrogen sulphid, after preliminary qualitative 
tests, was assumed to be absent, although it is of course possible 
that, if present originally in the gas, it may have been taken up by 
the mercury. That any of this gas occurs in the eyes is, however, 
very improbable, for its odor was never detected. For hydrogen 
sulphid and mercaptans the nose is many times more sensitive than 
is the spectroscope for sodium," and unless the other and milder 
odors of Swiss cheese exercise a surprisingly intense hindrance to the 
detection of hydrogen sulphid and mercaptans we may justly say 
that these vapors were absent. With Nessler's reagent very slight 
traces of ammonia were detected. For oxygen alkaline pyrogallol 
or long-continued contact with phosphorus was used. Combustible 
gases were estimated in several ways. Explosion with oxygen, in 
the presence of electrolytic gas when necessary, was used in several 
instances. For one case combustion with a platinum sponge was 
tried. For the small percentages of combustible gases found the 
method of Dennis and Hopkins ' was found to be the most satis- 
factory. This consists, essentially, in leading the gas slowly into a 
measured volume of oxygen and there burning it slowly and quietly 
with a platinum wire heated by an electric current. 

Tabi«e 1. — Analyses of gas collected by vunctwring apparatus from eyes of SwisB {Bhti^ 

mental) cheese — Method I. 



Deslg- 
Datiaa 

of 
dieete. 


Total 
vol- 
ume of 

KMOOl- 

toSted. 


Gontnctkni^ 


Compositfcin. 




Doe to 
absorp- 
tion 
with 
KOH. 


Doe to 
absocp- 

tkm 
forOi. 


Due 
to 
com- 
bus- 
tion. 


COi. 


0*. 


Hydro- 
car- 
bons. 


Hf 


N,. 


Desorfptkni of cTvwoe. 


a 


Ce, 

0.96 

2.73 

1.66 

4.77 

1.25 

/ S.44 

\ 4.02 

15.24 

/ 7.56 

4.09 

/ 14.47 

t 9.99 

6.48 

4.96 


Ce, 
0.66 
2.29 
1.11 
2.44 
1.00 
2.23 
2.52 

13.77 
6.14 
4.04 

12.91 
8.96 
3.04 
2.85 


Ce. 


Ce. 


Per 
eeni. 
57.3 
83.9 
66.9 
61.2 
80.0 
64.8 
62.7 
90.4 
81.2 
80.9 
80.2 
89.5 
56.0 
47.4 


Per 
cent. 


Per 
cenL 


Per 
eenL 


Per 
eent. 


Imported, eyes normal. 
Do. 


b 


aoo 

.01 
.02 
.00 
.00 

.66 

.02 
.03 
.08 
.01 
.02 
.01 


6.'i6' 

.02 
.00 
.60 
.45 
.76 
.43 
.30 
.00 
.09 
.06 
3.63 


0.0 

Trace. 

Trace. 

0.0 

0.0 

*'*'6'6' 

Trace. 
0.6 
0.2 

Trace. 

Trace. 

Trace. 








d 

e 

f 

g 
h 

i 
30.61 


0.0 
0.0 
0.0 
Trace? 
0.0 
0.0 
0.0 
0.0 

aor 
ao 


4.00 
Trace? 

ao 

11.6 
7.5 
3.3 
3.7 
4.0 

ao 
a 6 

Trace? 
48.8 


29.1 
48.8 
20.0 
23.6 
29.8 
6.3 
15.1 
14.5 

lae 

9.8 

44.0 

3.8 


Imported, ^68(7). 
Imported, eyes normal. 

Do. 
\Domestic. eyes thtokly 
/ crowded. 
Do. 

/ crowded. 

lExcellnnt Imparted, eyea 

/ very regular. 

Imported, lazse hole. 

Very gassy in press. 



12 



STUDY OF OASES OF EMBCBNTAL CHEBSE. 



The analyses of the gas collected by Method I are given in Table 1, 
and of that collected by Method 11 in Table 2. All volumes are for 
0^ C. and 760 mm. When the gases were collected from a cheese pro- 
cured at the market, a sufficiently large slice was purchased to pre* 
vent undue exposure of the eyes, and this was carried immediately 
the short distance to the laboratory, and the gas at once collected. 
In most cases the shaft pimctured or grazed more than one eye, so 
that the analysis gives the true average for several eyes. 

Table 2. — Analyses of gas collected by pumping from Swiss (Emmental) cheese — 

Jfethod IT. 



Ko. of 


Time 

pump. 

ing. 


Total 
looted. 


Weight 
of cheese 
evacui^ 

ted. 


Amount 

of gas 

per 100 

grams of 
cheese. 


Composition. 




dieese. 


CO,. 


0,. 


H,. 


N,. 


Description of cheese. 


3 


Homrt. 
20 

26' 

26* 


C.e. 
2.36 

2.31 

6.41 

3.20 

13.60 


OntM. 


C.C 


Per 
cent. 
76.3 

77.5 
80.8 
50.6 
84.5 


Per 

cent. 

1.7 

2.6 
2.0 
1.0 
2.2 


Per 
cent. 

ao 

0.0 

0.0 
0.0 
0.0 


Per 

cent. 
22.0 

19.9 
17.2 
48.4 
13.3 




81M5 






holes, etther pinholes or in- 
hibited eyes. 
Do. 


89-11-2 






Do. 


46-4-1 
W2 


50 
53 


6.40 
25.7 


Do. 
Fine domestlo cheese Just be- 
ginning eye deveJopment. 



DISCUSSION OF THE ANALYSES. 

If the values obtained in this study of the gases found in the eyes 
of Swiss cheese are compared with the values obtained by Boekhout 
and Ott de Vries * for the gases in Edam cheese, it is seen that the 
latter obtained much lower percentages of carbon dioxid and corre- 
spondingly higher percentages of nitrogen. The explanation becomes 
apparent when it is remembered that Boekhout and Ott de Vries 
collected the gas over water, while in this investigation it was collected 
over mercury. The two methods were compared in the case of cheese 
h, as follows: 



Method. 



Collection over mercory. . 
Collection over mercury. . 
Collection over water. 



CO^ 



Percent, 

81.2 
80.9 
34.8 



O,. 



Percent, 

Trace. 

0.6 

1.9 



Percent. 
3.7 
4.0 
1.0 



Nfc 



Percent, 
15.1 
14.5 
61.4 



This result is what might have been expected, namely, an absorp- 
tion of much carbon dioxid and a little hydrogen by the water, and, 
in return, an increase in the amount of oxygen as well as an increase 
in percentage of nitrogen. Boekhout and Ott de Vries have them- 
selves called attention to this, and claim only qualitative value for 
their results. The types of holes from which they isolated gas were 
small cracks corresponding to the Emmental ''riszler/' small round 
holes, and large cracks termed '' knijpers/' 



DISCUSSION OP ANALYSES. 13 

Qualitatively the composition of the gases was the same; namely, 
carbon dioxid, hydrogen, nitrogen, and oxygen. Of these they elimi- 
nated oxygen as due to contamination. In the case of the ''knij- 
pers," or large cracks, 52 to 249 c. c. of gas were collected instead of 
5 to 22 c. c. as in the case of the smaller holes. Assuming that the 
same volume of water was used, we would expect a truer value to be 
obtained for the analysis of the larger volumes, in which case the 
attention is struck by the large percentage of hydrogen. The signifi- 
cance of this will become apparent when the results on Emmental 
cheese have been assembled. 

It is dear from the analyses of gas found in Emmental cheese 
that carbon dioxid and nitrogen are the chief constituents of the gas 
found in normal eyes. The oxygen in most cases is hardly more than 
would be expected to come from the minute bubbles or surface 
layers which adhere to the glass walls of the apparatus. To what 
gas the contraction after explosion with oxygen is to be ascribed is a 
difficult question to settle. In some cases, where the contraction 
was sufficiently large to justify further absorption with potassium 
hydroxid, the absence of any further contraction in volume justifies 
the conclusion that the combustible gas was chiefly hydrogen. In 
other cases the small contraction might have been due to any one of 
a number of gaseous combustions. 

For further information it was decided to examine specimens of gas 
spectroscopically. The gas freed from carbon dioxid fjid possible 
oxygen was passed over phosphorus pentoxid into a dry, exhausted 
PlQcker tube. The discharge of an induction coil was then passed 
between aluminum terminals, and the spectrum observed with a 
prism spectroscope. At the same time comparison was made with the 
spectrum of a similar tube containing pure hydrogen. ^Minute traces 
of hydrogen are to be expected when metal terminals are used, but, 
with the low resolving power of the spectroscope employed, the nitro- 
gen spectrum so obscured the possibly present red line of hydrogen 
that it was not observed with specimens of pure nitrogen. A known 
sample of nitrogen containing about 0.05 per cent of hydrogen gave 
a brilliant hydrogen spectrum, whose intensity could be made more 
sharp at the expense of the nitrogen spectrum by suitable varying of 
the pressure." The recognition of 0.05 per cent of hydrogen was 
therefore assured. 

A small experimental cheese, which had begun an apparently nor- 
mal eye formation and then ceased entirely, was pumped out by 
Method II and its gas submitted to spectroscopic examination. 
Slight evidences of hydrogen were observed. Samples of gas taken 
from cheeses which yielded 3 per cent of combustible gas gave very 
brilliant evidences of hydrogen. 



14 



STUDY OF QA8E8 OF EMMBNTAL CHEESE. 




In samples of gas taken from the normal eyes of two cheeses pur- 
chased on the market no hydrogen line was observed, nor was the 
hydrogen spectrum observed in the gases of a normal cheese evolved 
during the period of its maximum eye formation. 

These results, though not eztensivei 
are sufficient to show that hydrogen 
plays no rdle in the formation of normal 
eyes, provided we assume that any hy- 
drogen formed has not escaped collection 
by rapidly diffusing through the cheese. 
To make sure of this point the following 
experiments were conducted: 

Two cheeses purchased in Wisconsin 
were found to be developing normal eyes. 
These eyes, though too thickly scattered 
for the modem market standard, would 
have been declared typical some years 
ago. When each cheese was apparently 
at the height of its eye formation, plugs 
were taken, and introduced into the tube 
A, figure 3, without that part illustrated 
at the side and lettered O, F, and E. To 
guard as far as possible against infection 
in transference the trier was flamed, and 
the tube was sterilized at 170® C, with 
cotton plugs at B and C. After intro- 
ducing the plugs of cheese they were fol- 
lowed by the flamed cotton plug and then 
a rubber stopper dipped in hot rubber 
cement. The stopper was forced in and 
held in place till the cement* had cooled, 
when several layers of the same cement 
were added to the exterior. This made 
a thoroughly gas-tight seal. The capil- 
Pio. 3.— Appaiatoa for studying the ab- lary end was now attached to the mercury 

wrptloa of oxygen by ofaeoe. *^ . « i ^* j ii 

pump by means of securely tied rubber 
tubing completely covered with a mercury seal. Then the tube was 
exhausted. 

Fortynaix grams from one of the Wisconsin cheeses were exhausted 
for two hours, dxuing which time it continued to give off small 
quantities of gas. The pressure was finally reduced to 2 mm. (meas- 
ured on a McLeod gauge). The stopcock D was then closed, and the 

A The cement was made by heating rosin severai days with as much fine-grade rubber as it would diawl ve. 
Dr. Nutting, of the Bureau of Standards, who kindly lUmisfaed the receipt, stated that he had used this 
oement In refined vacuum work with entire satisfaction. 



.^:^.- 







DISOUSSIOlSr OF ANALYSES. 15 

tube aUowed to remain in connecUon with the pump overnight. 
The next morning the pumping was resumed^ and a pressure of 2 mm. 
again obtained. The gas which had collected oyemight amounted 
to 7.23 c. c, N. T. P. Its analysis follows: 

C.c 

Qriginal volume 7.23 

Residue after absorption with KOH 17 

CO, 7.05 

Oxygen added up to o2,28 

Volume after combustion with heated platinum spiral 2. 26 

Contraction 02 

The tube was then sealed oflp in a blowpipe at the constriction H 
and kept for six days at 25^ C. To collect the gas from this sealed 
tube the following method was used. The capillary tip of the seal 
was scratched with a diamond, and then pushed up into the tube 
leading from the pump as at C, figure 3. Connection was made with 
a rubber tube securely tied and covered with a mercury seal. Having 
exhausted the pump up to the tip of the seal, the tube was turned 
slightly and sharply. The tip was broken at the scratch, and com- 
munication established between A and the pump. 

The gas thus collected at the end of six days amounted to 10.12 
c. c. The tube was allowed to stand connected with the piunp over- 
night, after which an additional 2.75 c. c. of gas were collected. 

These two volumes were united and analyzed 99.3 per cent carbon 
dioxid. The residue was hardly sufficient to justify further analysis. 
It was made, however, and a minute contraction observed, which was 
hardly more than the experimental errors of transference. 

Forty-five grams of the second Wisconsin cheese submitted to the 
same procedure as described above gave the following data: 

Co. 

Gas collected on first standing overnight 11. 48 

Residue after absorption with KOH 22 

COj 11.26 

Residue after absorption with phosphorus 22 

Oxygen added up to o 2. 41 

Volume after combustion with heated platinum spiral 2. 39 

Tube sealed off and incubated six days at 25^ C. 

C.e. 

Gas collected after 6 days 9.29 

Residue after absorption with KOH 16 

CO^ 9.13 

Oxygen added up to «4. 91 

Volume after combustion with hot platinum spiral 4. 85 

Gas collected after again standing overnight 5. 33 

Residue after absorption with KOH Trace. 

a This oompantiTely laxse volume was made neoeaaary because of the disadvantaceoua form of the 
Deosia-Hopkiiia pipette uaed. 



16 STUDY Ot OASEd 0^ ^MMfilfTTAL CHEfifiS. 

In the above analyses the contraction due to combustion was so 
small that further analyses to determine the products of combustion 
were impracticable. Nor was it necessary, for, even if the contraction 
were due to but one gas, for example hydrogen, the amount was such 
that this gas may be said to be without significance in the formation 
of eyes. Doubtless the contraction was in reality due to volatile 
organic bodies. The above experiments show that when all the gas 
from an actively gas-producing region is collected no significant 
amount of hydrogen is found, and thereby the contention is refuted 
that, in the analysis of gas in the eyes, hydrogen escaped detection 
because of its rapid diffusion put through the cheese. 

Pains were taken in these studies to make a strenuous hunt for 
hydrogen for the following reason: In Enmiental cheese there is 
what Duclaux has termed the 'initial fermentation" during which 
the sugar inclosed in the curd undoi^oes bacterial decomposition. 
Several of the earlier workers on this cheese thought it was the gaseous 
fermentation of this sugar which caused the development of eyes. If 
so, one would expect to find the gas composed of a large percentage of 
hydrogen, since hydrogen is a characteristic product in the f ermenta^ 
tion of sugars by bacteria. This deduction is of course not rigid, but, 
from our present knowledge of the gaseous fermentation of sugars by 
bacteria, it is highly probable. 

Jensen" in 1898 pointed out clearly that the gaseous fermenta- 
tion of sugar must not be looked upon as in any way directly connected 
with the production of normal eyes in Emmental cheese. He 
found no trace of sugar in a cheese five days old, although the normal 
eye formation had not yet begun. This confirms the analyses made 
by various authors. Jensen cited Klenze " as stating that the sugar 
disappears in 48 hours. But, while the sugar disappears rapidly, 
normal eyes seldom begin to develop before the eighth day, and reach 
the height of their development long after every trace of sugar has 
disappeared. 

These facts alone demonstrate that the eye formation does not 
depend upon the presence of sugar. Additional reason for so believ- 
ing is found in the results herein, in so far as the absence of hydrogen 
in the gas indicates an absence of gaseous sugar fermentation. 

But it also follows from this reasoning that when a gaseous fermen- 
tation occurs while sugar is stiU present in the cheese, hydrogen is to 
be expected. Such a fermentation frequently occurs while the cheese 
is in press. Fortunately a cheese was obtained (No. 39-61) which was 
known to have given marked signs of gas while under press. From 
this cheese gas was collected by the previously described Method I, 
with the following analysis : 

Total volume of gas collected Cubic centimeters. . 4. 96 

Kesidue after absorption with. KOH do 2. 61 

COj do.... 2.35 

Kesidue after absorption with phosphorus do. . . . 2. 60 



Dl60tT66lOK 6^ AI^ALWeS. 17 

Oxygenadded up to Cubic centimetera. . 6. 14 

Volume after combustion with platinum spiral do 2. 51 

Contraction do 3. 63 

Residue after absorption with KOH do 2. 51 

Hydrogen per cent. . 48. 80 

Upon attempting to mako a second puncture the mercury broke 
through into the hole previously made. The cheese was then opened, 
and foimd to be so spongy that the walls separating the individual 
cells were very thin — ^too thin to withstand the weight of mercury. 

To obtain a second sample of gas for confirmatory analysis recourse 
was had to Method II of collecting gas, previously described. A high 
percentage of hydrogen was again found. 

In the further study of this case 52 grams of the cheese were intro- 
duced into the vacuum tube described on page 14 and evacuated to 
1 mm. pressure. There collected overnight 7.84 c. c. of gas. 

Analysis: 

C.c. 

Total volume 7. 84 

Residue after absorption with KOH 28 

Residue after absorption with phosphorus 27 

Oxygen added up to 1. 08 

Volume after combustion with platinum spiral 99 

Contraction 09 

The tube was then sealed off and kept nine days at 25° C. Upon 
opening it and pumping out the gas by the method previously 
described 7.49 c. c. of gas were collected. The residue after absorp- 
tion with potassium hydroxid was only 0.07 c. c. 

It is therefore apparent that the production of hydrogen^ which 
was very active while the cheese was in press, had soon ceased, pre- 
sumably with the disappearance of the sugar. 

The occasional occurrence of hydrogen in small percentages, as 
shown in the table, generally accompanied eyes which in the writer's 
judgment were not typically normal. They were either crowded and 
distorted or associated with numerous pinholes. It is not, perhaps^ 
incorrect to say that in all probability there had occurred in these 
cases a slight initial gaseous fermentation of the sugar, with the pro- 
duction of hydrogen which lingered to contaminate the gas of the 
normal fermentation. 

An extremely interesting observation was made in the case of cheese 
i. (See Table 1, p. 11.) This was an excellent imported cheese with 
large and perfectly rounded eyes, well spaced in a body of fine texture 
and flavor. In the first analysis of the gas from these eyes no trace 
of a combustible gas was found. The second analysis gave 0.6 per 
cent of hydrogen. Upon exposing the eyes punctured it was 
observed that a slight crack extended to within a centimeter of one of 
the eyes punctured on the second collection. This crack was found 
to lead directly to a hole some 2 cm. in diameter, the irregular and 
apparently corroded walls of which proclaimed it distinctly abnormal. 



18 STUDY OF OASES OF EMBCENTAL CHEESE. 

It is of interest to note that in the case of cheese j, gas was obtained 
from a hole the size of one's fist; and that this contained practically 
no hydrogen. The appearance of this hole was that of a strictly 
normal eye except in size. 

It was hoped that the gas of a typical ''blow hole" could be ob- 
tained. For this purpose a cheese containing such a hole was pur- 
chased in "^^consin. When it arrived at the laboratory it was found 
that the cheesemaker had punctured it. 

From the results obtained it is clear that there are at least two 
distinct types of gas formation.** The one is highly detrimental, and 
is accompanied with hydrogen; the other is that demanded in a good 
Emmental cheese. One is dependent upon the presence of sugar; 
the other occurs in the absence of sugar. 

The presence of hydrogen in considerable quantities in the gas iso- 
lated from Edam cheese by Boekhout and Ott de Vries is very sug- 
gestive of a gaseous fermentation of sugar, and to this Jensen ^^ has 
ascribed the formation of gas holes in Edam cheese. 

At this point it may be well to call attention to a source of error 
overlooked by various investigators in their attempts to establish 
the cause of any particular gas formation in cheese. Frequent exam- 
ples are to be found in which gas production by bacteria in milk is 
interpreted to mean that these bacteria can produce gas in cheese. 
Although this may frequently be true, it must nevertheless be remem- 
bered that the two media differ not only in chemical constitution but 
also vary greatly in physical chemical condition. 

Baumann,' for instance, attributed the formation of eyes in hard 
cheeses to Bacillus diatrypeticus ccLsei. From an experiment in 
which this bacillus produced in milk gas containing 63 per cent of 
carbon dioxid and the remainder almost entirely hydrogen, Baimiann 
concluded that the gas of normal as well as faulty eyes is carbon 
dioxid and hydrogen. The error of attributing the reactions of a 
bacillus when cultivated in milk, which contains sugar, to cheese, 
which after the initial fermentation contains no sugar, is so evident, 
and the error in stating that the gas of normal eyes contains hydrogen, 
without having first analyzed this gas, is so evident, that Baumann's 
conclusions might be left imnoticed at this late date were they not 
typical of several found in the more recent literature. 

ABSORPTION OF OXYGEN. 

In all the analyses no appreciable amount of oxygen was found. 
The presence of large percentages of nitrogen with this absence of 
oxygen raises the question, Does air diffuse into the cheese with ab- 
sorption of oxygen ? Evidence of an active absorption of oxygen was 

a This does not predude there heing a number of distinot fenneatattons or reactions of either type. 



ABSOBPTION OF OXYGEN. 19 

accidentally obtained. In attempting to study the gases produced 
in sealed tubes a faulty form of tube was first used^ which evidently 
leaked. On attempting to exhaust, the lowest pressure which could 
be obtained was 3.6 mm. It was soon ascertained that there was no 
leak in the pump, but a leak in the tube was suspected. The tube 
was left connected with the pump (connecting stopcock closed) over 
night. The next morning 37.20 c. c. of gas was pumped out. The first 
portion of 19.16 c. c. gave 4.57 c. c. of carbon dioxid and 2.21 c. c. of 
oxygen. The residue was lost but was considered to be nitrogen. The 
second portion was then pumped out, and of the 18.05 c. c. thus col- 
lected there were 4.85 c. c. of carbon dioxid, 1.45 c. c. of oxygen, and 
the residue entirely nitrogen. The total oxygen amounted to 3.66 c. c, 
which, had it come by leakage, would have indicated an entrance of 
13.7 c. c. of nitrogen. There was actually found 24.12 c. c. of nitrogen. 
This leaves 10.42 c. c. of nitrogen to be accounted for. The carbon 

dioxid amounted to only 9.42 c. c. and, since the ratio q' is much 

larger than that obtained in other similar pumpings where no leak 
occurred, it was suspected that oxygen had been absorbed. 

To definitely determine tliis the apparatus shown in figure 3 was 
used. With plugs of cotton at B, C, and in the bend above G, the 
tube was sterilized at 170° C. Then 28.5 grams from one of the Wis- 
consin cheeses were carefully taken with trier and spatula flamed to 
prevent contamination as far as possible, and the plugs introduced 
into A and sealed in as previously described. Mercury-was drawn up 
into the tube E until it had just passed the stopcock F. After at- 
tachment had been made to the pump the whole was evacuated 5 
hours and finally at a pressure of 1.2 mm. the capillary at H was sealed 
off in a blowpipe flame. There was introduced into E 7.47 c. c. N. 
T. P. of oxygen from a tank. At the same time a sample of the same 
gas was taken for analysis, and found to contsun 98.1 per cent of 
oxygen. Upon opening the cock F atmospheric pressure forced the 
gas over into the tube A. The mercury behind this gas was allowed 
to rise until it had entered the capillary G. As close to this mercury 
as was possible G was then fused off with a blowpipe. There was 
left of the 7.47 c. c. iutroduced only a small bubble in the capillary, 
and this at reduced pressure. After 6 days at 25*^ C. the tube was 
opened by the usual method and the gas was pumped out and ana- 
lyzed, with the following result: 

c. 0. 

Total volume of gas collected 11. 90 

Carbon dioxid 10. 96 

Oxygen 53 

Residue, all nitrogen 41 

From the percentage composition of the 7.47 c. c. of gas added 
at the beginning of the experiment it is known that 7.33 c. c. of 



20 STDDT OF OASES OP EUHENTAL CHEESE. 

oxygen was added. At the end of the experiment there remained 

only 0.53 c. c. of oxygen. There must, therefore, have been 6.80 c. c. 

of oxygen absorbed, or 0.239 c. c, per gram of cheese. 
Such an active absorption of oxygen lends itself to the argument 

that the nitrogen of the ^es found its way there by the diffusion in of 
air. But, before such an argument can be con- 
sidered vaUd, the following points must be deter- 
mined : First, to what extent is cheese permeable 
to gases in general and nitrogen in particular ? 
Second, how much of the nitrc^en present is due 
to nitrogen dissolved in the cheese at the time of 
manufacture 1 Third, what evidences are there 
to show that the nitrogen does not arise in situ 
from bacterial or chemical reactions ? 

TBE PERHEABILnr OF CHEESE TO GASES. 
After various unsuccessful efforts to make an 
impermeable adhesive that would stick to 
cheese, and so enable a slice to be sealed into 
a diffusion apparatus, the following device was 
made (fig. 4): 

At B a membrane of plaster of Paris was 
formed whose strength was reenforced by a per- 
forated brass plate not shown in the diagram. 
This membrane was desiccated until its perme- 
abihty was high, that of transfusion.'" 

Most of the air was forced out of D through 
the membrane and E by raising the mercury. 
A carefully taken disk of cheese was then 
placed on the plaster of Paris bed. It was 
gently held there while it was completely cov- 
ered with mercury. Then, by lowering F, the 
space in D was left under greatly reduced pres- 
sure. This caused such a difference in pressure 
between the upper and lower surfaces of the 
Fia. 1.— DOTke br ksoertab- cheese that the disk was held firmly against the 
fngpenoMbiiiiyoiohefflato plaster bed, and tho surroumling mercury was 
unable to float it. Preliminary experiments 
showed that no mercury crept between the disk and the plaster, 
and that the plaster did not become clogged with mercury or cheese. 
After partial vacuum had been produced in D a few moments elapsed 
before the gas retained in the plaster came to equilibrium. When 
this was reached the mercury was carefully withdrawn from the top 
of the disk of cheese until the surface was exposed. The mercuiy 



PEBMEABILITY OF CHEESE TO GASES. 21 

left at the side prevented entrance of gas there, so that the only 
path between the chambers A and D by which gas could enter D was 
through the cheese. 

The disks of cheese used were about 1 cm. in diameter and 2 to 
2.5 mm. thick. They were taken from sound portions of freshly cut 
cheese by means of a cork borer, and carefully sectioned with a sharp 
razor. Every precaution was used in cutting and handling to pre- 
vent distortion and breaking of the texture. In one case the exposed 
surface was that of an eye. The gas whose diffusion it was desired to 
study was flooded into the chamber A. With both air and carbon 
dioxid there was apparently no diffusion during an hoiu*, even though 
the pressure in D was reduced as much as possible. Longer experi- 
ments were not practicable, because a continuous watch had to be 
kept to see that no bubble of air entered through the rubber connecting 
tube between D and F and altered the volume in D. With a trap to 
prevent such a source of error the same impermeability for air was 
observed during an experiment lasting several days. 

This result was so remarkable that it was tested further in the 
following manner: Instead of the parts E, D, F (fig. 4), a glass tube 
led from B to a mercury pump. With the cheese slab C covered with 
mercury the pump was operated tiU the lowest vacuum which could 
be obtained was reached. By reason of the gas being given off by the 
cheese, this was of course not so high a vacuum as the pump can 
produce. When the vacuum was considered sufficient the pump was 
allowed to rest in order to discover leakage, and, if there were none, 
to allow the residual gas to distribute itself so that a reliable reading 
on the McLeod gauge could be made. Then the mercury was care- 
fully withdrawn from the top of the cheese, leaving its upper surface 
exposed. Entrance of gas could now be detected by the McLeod 
gauge. An experiment is given in detail below: 

[Disk of cheese 7 mm. diametpor, 2.5 mm. thick, taken 10.60 a. m., Dec. 19, 1911, 15mm.from the nearest rind.] 



Apparatus exhaustedj and, with cheese covered with mercury, pump pressure at . 
Pump resting 

Increase in pressure assumed to be due to gas evolved from cheese. 

After 7 minutes pumping 

Cheese exposed to air 

Do 

Do 

Do 

Do 

After 15 minutes pumping 

Cheese exposed to COt 

Do 

After 5 minutes pumping 

Cheese exposed to Ht 

Do 

After 15 minutM pumping 

Cheese left oremi^t exposed to air 



Time of 


Pres- 


reading. 


sure. 


a.m. 


Mm. 


11.14 


0.075 


11.25 


.140 


11.30 


.150 


11.37 


*.070 


11.40 


.070 


p.m. 




12.15 


.160 


1.16 


.270 


1.60 


.320 


2.16 


.360 


2.30 


.025 


3.10 


.060 


3.30 


.090 


3.35 


.025 


4.10 


.060 


4.30 


.065 


4.45 


.010 


a.m. 




0.30 


.430 



22 STUDY OF OA8E8 OF EMMENTAL CHEESE. 

When the disk of cheese and the mercury were removed air entered 
rapidly, showing that the plaster had not become plugged. Further- 
more, there was no evidence of mercury having crept between the 
cheese and the plaster. It is not claimed that all the above listed 
readings on the McLeod are very accurate, since the readings were 
sometimes made before equiUbrium was obtained. All that was 
desired was the order of magnitude. Since the variation in tempera- 
ture during the experiment was only between the extremes 17° C. 
and 19° C. and since the volume of the pump, gauge, and diffusion 
apparatus was found to be 159 c. c, we may calculate from pressures 
the approximate amoimt of gas which had apparently diffused through 
the cheese. This amounted to about 0.09 c. c. during the first 5 hours 
and 0.09 c. c. during the last 17 hours. 

Allowing nothing for possible small leaks, which were difficult to 
avoid in the delicate manipulations required, the observed volume of 
gas indicates a very remarkable impermeability. Practically the 
same result was obtained with a disk of Cheddar cheese and other 
samples of Swiss cheese. 

The question at once arises. How to explain the evolution of carbon 
dioxid which there is every reason to suppose does diffuse from cheese ? 
Van Slyke and Hart " found that a normal Cheddar cheese evolved 
during 32 weeks 15.099 grams of carbon dioxid. Since they took 
care to exclude surface growths of molds, it seems highly improbable 
that this amount of carbon dioxid could have come to any great 
extent from the surface layers alone. It must have diffused from 
the interior of the cheese into the surrounding bell jar. 

The following explanation will doubtless be found reasonable: 
Becquerel * found that when the tegument of peas was mounted at 
the end of a barometer tube, and a partial vacuum of 5 to 10 mm. 
obtained upon the one side, with atmospheric pressure on the other, 
the tegument was impermeable to gas when dry, although permeable 
when moist. In so far as the tegument of peas and a disk of cheese 
are both colloidal they may be compared! In the present experi- 
ments the disks of cheese dried considerably both from exposure to 
gases of low vapor content on the one side and the moisture free 
vacuum on the other. By analogy with BecquerePs experiments 
one would expect to find the dry cheese more or less impermeable. 
Reference to the experiment detailed on page 21 wUl indeed show that 
the permeabihty decreased as the time of the experiment increased, 
or, in other terms, as the cheese became drier. Furthermore, in 
an experiment in which the exposed surface of the cheese was kept 
exposed to carbon dioxid, which was saturated with vapor, 1.04 c. c. 
of gas was found to have passed through in 5 hours; ten times as 
much as in the experiment with diying cheese. 



PERMEABILITY OF CHEESE TO GASES. 23 

It therefore seems probable that the permeability of cheese to gases 
is due to the diffusion of dissolved gases, and that as the free solvent 
becomes more and more attenuated the gas is more and more unable 
to find its way through the gel. 

Since in Emmental cheese a more or less dry rind is produced, it 
seems probable that little air can diffuse into the cheese. And from 
the fact that in the manufacture of Cheddar a less dry rind as well as 
a more open texture is produced, it seems probable that escape of 
carbon dioxid more easily occurs in this type than in the Swiss type 
of cheese. 

It must be remembered, however, that the above experiments only 
cover a very limited time, and that, even were the permeability as 
low as the experiments seem to show, there is still the possibiUty that 
nitrogto may make its way slowly through the gel during the long 
period of ripening. Possibly more extensive investigation would 
reveal that the larger percentages of nitrogen found in the eyes of 
some cheeses are proportional to the age of the cheeses. Neverthe- 
less this penetration can only take place slowly. 

The fact that penetration of air is so slow, together with the 
avidity with which oxygen is absorbed, only tends to emphasize the 
completeness of the anaerobiosis in the interior of the cheese, a con- 
dition which Troili-Peterson " found necessary for the best develop- 
^ment of the propionic bacteria. 

These experiments on the permeability of cheese to gases make it 
evident that in pumping the gases from plugs of cheese we should ex- 
pect the gas to be slowly evolved. Such was, indeed, found to be the 
case. The reason for this was not fully appreciated at the time the 
pumpings were made, and it is very doubtful if all the occluded gas 
was completely exhausted even after 20 hours exposure to high 
vacuum. Reference to the experiment with plugs of cheese kept 6 
days in vacuo (p. 15) reveals the interesting fact that the amount of 
gas evolved per gram of cheese was dependent more upon the state 
of the vacuum than upon time. This is iQustrated in the following 
statement, in which the figures represent cubic centimeters of gas 
evolved per gram of cheese per hour: 




Flnt 18 hoots 

Stwoeeding 6 days. 
Last 18 houiB 



0.0067 
.0015 
.0033 



a0042 
.0014 
.0066 



During the middle period, of course, the tubes were sealed, and the 
evolved gas increased the pressure. Evidently^ then, the higher the 
vacuum to which the sample was subjected the more rapidly was the 
gas evolvedi indicating that a considerable proportion of the ^as was 



24 8TUDT OF OASES OF EMHENTAI. CHEESE. 

dissolved or occluded gas rather than that fonned during the time 
of the experiment. 

It may also be true that there is loose combination of carbon 
dioxid with inorganic salts, or with calcium and amino bodies, as in 
the carbo-amino reaction, and that the stability of these compounds 
is a function of the imposed pressure. 

HITROGBIT DISSOLVED HT CURD. 
Let us now consider how much of the 
nitrogen found in the eyes is attributable 
to nitrogen occluded in the original curd. 
One would expect the curd to be well 
aerated by the vigorous stirring it gets 
during the process of manuf acturei Mar- 
shall '* has shown that aerated milk con- 
tains con^derable quantities of nitrogen, 
but, unfortunately for the purposes de- 
sired, his data are only expressed in per- 
centage composition and not very defi- 
nitely in cubic centimeters of gas per 
cubic centimeter of milk. 

A rough approximation of the amount 
of nitrogen occluded in tlie curd was 
obtained in the following way: A liter 
of milk was treated as in the process of 
making Swiss cheese. When the curd 
had reached the stage when it was suit- 
able to hoop, the greater part of the 
whey was decanted, and then the re- 
sidual whey and curd were poured care- 
fully into the glass cylinder A, figure 5 
(inverted). As the curd settled, the 
overlying whey was drawn oflE and more 
of the mixture poured in. This was re- 
peated until the tube was filled with curd 
grains completely surrounded by whey. 
The rubber stopper was then forced in. 
The tube was next inverted to the posi- 
Fio. s.^App«™tn»te dBPacminiiig j^^^ ghown in the figure, and the mer- 
cury seal stopcock it was opened to re- 
lieve the pressure. The rubber stopper was then forced farther in, 
and the whey displaced by it escaped into C. By covering the 
stoppered end of the tube with rubber-rosin cement and keeping 
it under mercury, it was made perfectly gas tight. The cock B was 
then clt)sed, and, after the surplus whey in C had been drained out, 
the apparatus was connected to the vacuum pump in the usual way. 



KITBOGEK DISSOLVED IN GUBD. 25 

When the pump and chamber C were completely exhausted, the 
cock B was opened. It was foimd that the gas expanding m A 
drove the whey ahnost completely up through the interstices of the 
curd and into C. 

An interesting point was observed. Comparatively little of the 
gas came from the whey^ while the major portion came from the ctird 
particles. Since a separation of whey and curd was accomplished, 
it could not have been true that the gas evolved from the curd par- 
ticles originated in the whey, using curd particles as nuclei for the 
formation of bubbles. Furthermore, there was comparatively little 
frothing of the whey in C, most of the gas collected having bubbled 
through C from A. Examination of curd particles will show why 
this is so; for they have adhering to them minute bubbles, apparently 
froth taken up during the stirring. It is quite evident that the col- 
umn of whey in C through which the gas had to make its way pre- 
vented a very complete exhaustion. Since the pumping was con- 
tinued several hours and the tube then allowed to stand overnight 
before the final pumping, this error was reduced to some extent. If 
occasion arises to repeat these experiments this error will be avoided. 

By the method described, 1.35 c. c. of gas was collected in one 
instance and 0.86 c. c. in another. Of this, there was 0.58 c. c. of 
nitrogen in one case and 0.39 c. c. in the other; average, 0.5 c. c. 
The curd was roughly estimated to represent 20 grams of cheese. 
Consequently there would be approximately 2.5 c. c. of nitrogen 
per 100 grams of cheese. How this nitrogen would partition itself 
between the body of the cheese and an eye is a question whose solu- 
tion would be mere guesswork without further data. 

While the 2.5 c. c. per 100 grams of cheese is a mere approximation, 
and a figure which would vaiy not only with the extent to which the 
curd is starred, but also with the form of the curd particles and their 
ability to absorb foam, nevertheless it is sufficiently accurate to 
show that a large part of the free nitrogen found in cheese comes from 
occluded air. 

DOES NITBOOEN ORIGINATE IN SITUf 

The question of whether any of the nitrogen found in the eyes is 
set free in situ is a difficult one to answer, and one which can not be 
definitely answered without further research. From the following 
considerations, however, it is highly probable that it is not produced 
diuing the course of that reaction which furnishes the gas to distend 
the eyes. In those experiments in which samples from a cheese at 
the period of its maximum eye formation were held in vacuo, the 
nitrogen in the evolved gas steadily and rapidly declined in per- 
centage, finally reaching almost nothing. This indicates that the 
nitrogen collected was simply that dissolved in the cheese, and as 



26 STUDY OF OASES OF EMMENTAL CHEESE. 

this was removed there was no evolution of free nitrogen to take its 
place^ such as occurred in the case of the carbon dioxid. 

RELATION BETWEEN CARBON DIOZID AND VOLATILE ACIDS. 

The results of the whole investigation show clearly that the only 
gas which plays an important rdle in the formation of normal eyes is 
carbon dioxid. This is in entire harmony with the assumption which 
has heretofore been accepted as a fact by various authors. 

It remains to be seen whether there is any quantitative relation 
between the amount of carbon dioxid evolved and that called for by 
the process to which Von Freudenreich and Jensen ascribe the forma- 
tion of eyes. 

A study of the volatile fatty acids of Emmental cheese by Jensen *' 
disclosed the fact that they are chiefly propionic and acetic, and that 
often the ratio of these approximates 2:1. 

Fitz ^ had previously shown that certain bacteria are capable of 
producing this ratio of propionic and acetic acids from lactic acid, 
and he ascribed to their action the equation: 

3C,HeOa=2CaH«03-fC2HA+C02H-HaO 

lactic propionic acetic 

Subsequently Von Freudenreich and Jensen • isolated from Emmen- 
tal cheese an organism which did ferment lactates according to the 
above equation of Fitz, and whose introduction into cheese was fol- 
lowed by an eye formation of which it was thought to be the cause. 

The conclusion seems evident that here is an organism to whose 
action may be attributed the formation of normal eyes. 

The evidence is undoubtedly the clearest that has yet been presented. 
^ There are, however, one or two points which will bear inspection 
before the theory can be accepted as a full explanation. 

According to the equation of Fitz three molecules of volatile fatty 
acids are accompanied by the liberation of one molecule of carbon 
dioxid. Consequently it can be shown that a titer of 1 c. c. of 
tenth-normal alkali for these volatile fatty acids should indicate the 
liberation of 0.74 c. c. of carbon dioxid (N. T. P.)._If, then, it is 
found that the volatile acids from 100 grams of cheese neutralize 100 
c. c. of tenth-normal alkali, and it is assumed that these acids are 
acetic and propionic in the ratio in which they occur in Fitz's equa- 
tion, we would have Uberated 74 c. c. of carbon dioxid per 100 grams 
of cheese. 

Tliis amount of gas is considerably more than is required to fill the 
eyes, but the question remains how much is to be found in the body 
of the cheese itself. 

Reference to the experiments described on page 15 shows that at 
an age of 55 days 37.2 c. c. of carbon dioxid per 100 grams of cheese 



BELATIOir BETWEEN CABBON DIOXID AND VOLATILE ACIDS. 27 

were collected after the cheese has been held in vacuo one week. At 
the time of the experiment it was thought that this gas was produced 
during that week. After the study which shows how impermeable 
cheese is, this view had to be modified, for, even after considerable 
pumping, an appreciable quantity of gas must have remained and 
appeared as "evolved" gas at the end oif the week. * In order to make 
a better estimation of the dissolved gas, plugs of this same cheese (at 
an age of 4 months) were sliced into thin disks to facilitate the removal 
of dissolved gas, and introduced into a tube. They were sealed in 
with the usual rubber stopper and rubber-rosin cement, and the tube 
joined to the merciyy pump. After evacuating the pump the con- 
necting cock was opened and the disks of cheese evacuated. The air 
surrounding them in the tube was of course pumped out too. The 
total gas thus collected after 5 hours continuous pumping contained 
17.05 c. c. of carbon dioxid. The weight of cheese was 42 grams. 
Hence, there were collected 40.6 c. c. of carbon dioxid per 100 grams of 
cheese (19 hours later 0.9 c. c. of carbon dioxid was collected, or 2.1 
c. c. per 100 grams of cheese). 

A duplicate determination gave 46.2 c. c. of carbon dioxid per 100 
grams of cheese (with an additional 1.03 c. c. per 100 grams after 19 
hours). The average for the first 6 hours' pumping was 43.4 c. c. of 
carbon dioxid per 100 grams of cheese, and this we may fairly con- 
sider the quantity occluded at the time the plugs were taken. At 
the same age (4 months) the volatile fatty acids corresponded to 40.9 
c. c. of tenth-normal alkali per 100 grams of cheese. 

Similarly, duplicate determinations of dissolved carbon dioxid and 
volatile acids in an excellent imported cheese (No. i) gave the fol- 
lowing data: Carbon dioxid per 100 grams, 67.8 c. c. and 54.8 c. c, 
average 61.3 c. c. Total volatile fatty acids in cubic centimeters of 
tenth-normal alkali per 100 grams 95.1 and 97.7, average 96.4. 

Assuming that aU the volatile fatty acids were produced in strict 
accordance with the equation of Fitz, the amount of these acids in 
the first cheese indicates that there had been liberated 30.6 c. c. of 
carbon dioxid against 43.4 c. c. found occluded; and in the second 
cheese the liberation of 71.3 c. c. of carbon dioxid against 61.3 c. c. 
found occluded. There is a somewhat striking apparent relation- 
ship in this data, and the averages, 51.0 c. c. calculated, against 
52.3 c. c. found, are in such dose agreement that they are tempting. 
A little consideration will show, however, that this agreement may be 
only accidental. At the time these analyses were made each of the 
chetees had probably reached a state of little activity. The volatile 
acids represent almost entirely the total amount produced in the 
interior from which the samples for analyses were taken; while, if 
we are to accept the results on Cheddar cheese by Van Slyke and Hart 
as at all applicable to Emmental, it is certain that a considerable 



28 STUDY OF QASBS OF EMMEKTAL CHEESE. 

quantity of carbon dioxid must have escaped in the months since 
manufacture. Furthermore, although the actual volume of the eyes 
represents but a small portion of the gas in a given volume of cheese, 
the normal volume of this gas in the eyes leaps into considerable 
significance when it is remembered that it must have been under 
considerable presstire. That it is under pressure was made evident 
in some cases by its vigorous escape when using the puncturing 
apparatus for its collection. 

Unfortunately long delay in obtaining apparatus suitable for a 
study of the gas escaping from cheese, as was done by Van Slyke and 
Hart for Cheddar, have made it impossible to present any data on 
this point. As before mentioned, the data on carbon dioxid evolved 
from plugs of cheeses taken at thiB height of their gaseous fermenta- 
tion and kept in vacuo a week is complicated by the fact that there 
was probably a alow yielding of dissolved gas from the solid plugs as 
well as the normal production of gas. Two other experiments, how- 
ever, indicate to what extent carbon dioxid was being formed during 
this period of maximum fermentation. 

Portions of cheese W 2 from regions without eyes were carefully 
selected and sealed up in a tube as described on page 14. The eye 
membranes were carefully removed from a large number of eyes 
and similarly treated. The tubes were simultaneously exhausted 
with a Boltwood pump for several hours. Since in these cases the 
cheese was in a more finely divided state, it is reasonable to assume 
that predissolved gas was pretty thoroughly removed. After exhaus- 
tion, the tubes were sealed off in a blowpipe flame and held at 25^ C. 
for seven days. At the end of this period the gas was collected: 

34 grams eye membranee gave 14.95 c. c. of gas, 99.3 per cent of carbon dioxid, 

or 44 c. c. per 100 grams. 
36 grams from regions without eyes gave 10.06 c. c. of gas, 98.2 per cent of carbon 

dioxid, or 28 c. c. per 100 grams. 

From this one pair of experiments it is not advisable to claim con- 
fidently that the eye surfaces always produce the much larger quantity 
of carbon dioxid, although this is plainly evident in the above case. 
The significant fact is that such a large quantity was produced by 
each region in the period of only one week. Of course it may be 
claimed that although the division of the cheese was done in a dust- 
free room and with sterile instruments, and the cheese introduced 
into sterile tubes, yet the long manipulation admitted a heavy 
reinoculation by bacteria, and that these produced a renewed evolu- 
tion of carbon dioxid. Such an ai^ument can not be completely 
refuted, but the probability of a heavy enough infection is small. 
The most likely source of carbon dioxid producing infection was by 
molds, but these could not have grown in the complete anaerobic 
condition in which the cheese quickly found itself. 



BELATIOK BETWEEN GABBON DIOXID AKD VOLATILB ACIDS. 29 

The following experiment serves to confirm the last. Into a steri- 
lized combustion tube were quickly slipped plugs of cheese taken 
with sterile instruments. Each end of the tube was guarded with 
cotton plugs. Carbon dioxid free air was then passed through, and 
the carbon dioxid evolved from the cheese absorbed in the customary 
train with all due precautions for exact estimation of carbon dioxid. 
In the case of this experiment we woidd expect a higher amount of 
carbon dioxid, since there would be collected not only the carbon 
dioxid produced, but a large portion of the predissolved carbon 
dioxid. Such was found to be the case. 

One hundred and five grams in plugs taken from cheese W 1 when 
at the height of its fermentation gave: 

First 24 hours, 81.6 c. c. of carbon dioxid. 
Second 24 houra, 66.7 c. c. of carbon dioxid. 
Third 24 hours, 44.5 c. c. of carbon dioxid. 
Fourth 24 hours. 63.7 c. c. of carbon dioxid. 

The increase on the fourth day was thought to be due possibly to 
growth of molds with which Van Slyke and Hart found difficulty in 
their work on Cheddar cheese. The experiment was therefore dis- 
continued, although no growth was visible. 

A final word must be urged against the too liberal use of the equa- 
tion of Fitz. As a terse representation of the probable relation of 
the end products the equation has a legitimate use. As a compre- 
hensive portraiture it is colored with presumption. The literature of 
fermentation is Uttered with equations, two or three members of 
which are known to stand in certain quantitative relationships, while 
the other members are given values which fit. This stoichiometrical 
adjusting is particularly true of the gaseous products. One has only 
to review the literature on the gas production of B. coli to assure 
himself of the fact. 

While Von Freudenreich and Jensen's use of the Fitz equation has 
been interpreted quite rigidly in the preceding pages, this was done 
simply as a test. From this basis alone one can not reasonably jump 
to a final conclusion; but it must be remembered that the liberal use 
made of the Fitz equation was generous to the theory of Von Freuden-- 
reich and Jensen in that aU the volatile fatty acids, as determined by 
Jensen's method, were assumed to have been produced in accordance 
with this equation. 

From a comprehensive view of the matter it appears to be quite 
evident that the theory of Von Freudenreich and Jensen is not 
capable of accoimting for all the carbon dioxid produced. Indeed, 
it is not necessary nor expected that it shoiild, but we have reached a 
point where it has become advisable to distinguish between a primary 
and a secondary cause of eye formation, and to at least define clearly 
what we mean when we attribute to any organism or to any reaction 
the function of forming eyes. 



80 STUDY OF GASES OF EMlffENTAL CHEESE. 

Suppose that the propionic bacteria are active, but that they are 
never sufficiently localized to concentrate carbon dioxid rapidly enough 
at one point to produce an eye. In this case the gas would be more 
or less evenly produced throughout the body of the cheese. Now 
this state of more or less complete saturation of the body with car- 
bon dioxid is exactly the condition necessary for the most advan- 
tageous eye formation by any other reaction which may follow, else 
the gas evolved at a point would be laigely absorbed and its inflating 
energy dissipated. Of course it can be said that this saturation 
proceeds from the point where the eye is formed, and that the delay 
observed before an eye commences to grow represents the time 
necessary to effect this saturation. 

This, however, is merely presenting the other horn of a dilemma 
from which escape is possible only when the localization of the propi- 
onic bacteria is conclusively demonstrated. Gorini * has contended 
that the localization of colonies may often be of as great importance 
as their isolation; and it is interesting to note that he found no cor- 
relation between the colonies which stained on his sections of Grana 
cheese and the gas bubbles. 

If, then, we distinguish between a '' saturating'' gas production 
and an ''inflating" gas production, we will have at least defined a 
possibility which must be squarely met, and a hypothesis which may 
lead to a differentiation between a primary and a secondary cause of 
eye growth. 

The favorable results obtained with cheese inoculated with pro- 
pionic bacteria indicate that they may play an important r61e. But 
is this r61e primary or secondary ? Is it a strictly localized action or 
is it simply the provision of that saturation without which some 
primary and strictly localized reaction would be without avail ? The 
same question arises in the case of the glycerin-fermenting bacteria 
to which Troili-Petersson *• has ascribed an important rdle in the 
holing of Swedish cheeses. In fact experimental cheesemaking of the 
past, though not so thoroughly controlled as in the experiments of 
Troili-Petersson and thos^ of Von Freudenreich and Jensen, bear 
evidence that any one of a number of gas-producing bacteria may 
provide the saturation, not to mention those reactions which Van 
Slyke and Hart " have proposed as contributing to the carbon dioxid 
in Cheddar cheese. On the other hand, any one of these may be the 
primary "inflator" and the other the secondary ''saturator." 

In this connection it may be of interest to note a peculiar phe- 
nomenon met with in some experimental cheeses. A number of 
these made with "artificial" rennet by Mr. Doane were reported in 
their early stages to have begun a normal eye formation. Seldom, 
however, did tins beginning develop into a normal holing. These 
cheeses were of small size, and, since it is known that small-sized 
cheeses for some reason not yet clearly defined seldom develop large 



8UMMABY, 81 

eyes, the failure in these cases may on general principles be vaguely 
attributed to size. However that may be, it was found upon pump- 
ing out the dissolved gas that the amount was low. The three 
cheeses examined were 39-45, 39-11-2, and 46-4-1. (See Table 2, 
p. 12.) 

It is well known from the work of Jensen and others that the bac- 
teria found in "natural" rennet are often distinct from those found 
in ' 'artificial" rennet. Since the cheeses under discussion were made 
with the latter, is it not possible that the reaction which started the 
eye formation was rendered inadequate because the gas-producing 
propionic bacteria, which might have saturated the cheese with 
carbon dioxid, were absent? That the observed holes were truly 
the beginnings of normal eyes, and were not a pinhole formation 
resulting from an initial gaseous fermentation of sugar, is evinced 
by the fact that hydrogen was absent. 

Exhaustive research alone can unravel this tangle; but it is hoped 
that the present investigation has provided both a clearer definition 
of the problem and a sound basis of fact. 

SUMMARY. 

1. The gases of normal "eyes" in Emmental cheese are exclu- 
sively carbon dioxid and nitrogen, and of these only the carbon 
dioxid is of significance. 

2. The nitrogen accompanying the carbon dioxid in normal eyes is 
that of air originally occluded in the curd at the time of manufacture. 

3. There sometimes occurs during the initial fermentation an evo- 
lution of gas characterized by the presence of hydrogen. This is 
believed to be due to the gaseous fermentation of sugar. 

4. The hydrogen from such an initial fermentation may sometimes 
linger to contaminate the gas of normal eyes. 

6. The two fermentations are distinct and are characterized by their 
gaseous products. The one is detrimental, the other that demanded 
of a good Emmental cheese. 

6. High oxygen-absorbmg power combmed with low permeability 
of the cheese to air render the interior thoroughly anaerobic, and conse- 
quently favorable to the growth of anaerobic bacteria. 

7. A comparison between the amount of carbon dioxid evolved 
and the total volatile fatty acids shows that the activity of the pro- 
pionic bacteria of Yon Freudenreich and Jensen is not sufficient to 
account for all the carbon dioxid found. 

8. It was found that cheese is capable of retaining a very large 
amount of carbon dioxid. 

9. The possibility is suggested that there are two phases in the for- 
mation of normal eyes, a saturation of the body with carbon dioxid, 
and an inflation of eyes; and the bearing of this hypothesis on the 
production of gas by a specific cause is discussed. 



82 STUDY OF OASES OF BMHENTAL CHEESE. 

RBFBRBNCBS TO UTERATURB. 

1. [BXcHLSR, 0. BeitrSge zur ErfoxBchung dea GShrungsverlaufefl in der Emmen- 

thaler Kfiaefiibrikation. Schweizeriaches Lmdwirtuchaftlichen Gentndblatt, 
Heft 1-6, 1896, cited by Jensen.] 

2. BoBKHouT, F. W. J., and Ott db Ybibs, Jan Jacob. Sur deux d^nts du 

fromage d'Edam. Revue G^n^rale du Lait, vol. 8, No. 14, p. 31^-^22; No. 
15, p. 347-356. Lierre, Sept. 30, 1910. 

3. Baumann, Fbetz. BeitrSge zur Erforschung der Kfteereifung. Die Landwirt- 

Bchaftlichen YerBucba-Stationen, vol. 42, p. 181-214. Berlin, 1893. 

4. bBCQUBREL, Paul. Sur la perm^bilit^ aux gas de I'atmoapb^, du tegument 

de certaines giaiaee dees^to. Acaddmie des Sciencea, €k>mptea Rendus, 
vol. 178, No. 22, p. 1347-1349. Paris, May 30, 1904. 

5. Dbnnis, L. M., and Hopkins, C. G. Die Beatimmung von Kohlenoxyd, Methan 

und Wasseratoff duich Verbrennung. Zeitschrift fOr Anoiganiache Chemiey 
vol. 19, p. 179-193. Leipzig, 1898. 

6. FiscHBR, EiOL, and Pbnzoldt, Franz. Ueber die Empfindlichkeit dea Qeradis* 

sinnea. Annalen der Ghemie, vol. 289, No. 1, p. 131-136. Leipzig, 1887. 

7. Fnz, A. Ueber Spaltpilzgfihrungen. VI. Mittheilung. Beridite der Deut- 

- schen Chemischen Geaellschaft. Vol. 13, p. 1309-1312. Berlin, 1880. 

8. VoN Frbudenrbich, Edward, and Jensen, Orla. Recberches sur la fermenta- 

tion propionique dans le fromage d'Emmental. Annuaire Agricole de la Suisse, 
vol. 7, No. 4, p. 221-242. Bern, 1906. 

9. GoRiNi, GoNSTANTiN. SuT la distribution des bact^ries dans le fromage de Grana. 

Revue G6n^iale du Lait, vol. 3, No. 13, p. 289-293. Liene, Apr. 15, 1904. 

10. Graham, Thomas. Chemical and physical researches. Edinbu^, 1876. 

11. Jensen, Orla. Studien Qber die Lochbildung in den Emmenthaler Eftsen 

Centralblatt fdr Bakteriologie, Parasitenkunde und Iniektionskiankheiten. 
Abteilung 2, vol. 4, No. 6, p. 217-222, Mar. 22; No. 7, p. 265-275, Apr. 1; No. 
8, p. 325-331, Apr. 26. Jena, 1898. 

12. Jensen, OniiA. Studien Qber die flflchtigen Fettsftoien im Kfise nebst Beit- 

rfigen zur Biologie der KSsefennente. Centralblatt ffir Bakteriologie, Para- 
sitenkunde und Infektionskiankheiten, Abteilung 2, vol. 13, No. 5/7, p. 161-170, 
Oct. 7; No. 9/11, p. 291-306, Oct. 21; No. 13/14, p. 428-439, Nov. 1; No. 16/17, 
p. 514^27, Nov. 11; No. 19/20, p. 604-615, Nov. 26; No. 22/23, p. 687-705, 
Dec. 10; No. 24, p. 753-765, Dec. 28. Jena, 1904. 

13. [Klbnzb. Handbuch f Or Kfisereitechnik, p. 198, cited by Jensen.] 

14. Marshall, Charles E. The aeration of milk. Michigan Agricultural Experi- 

ment Station. Special bulletin 16, Agricultural College, 1902. 

15. NxTTTiNO, P. G. The spectra of mixed gases. Astrophysical Journal, vol. 19, 

No. 2, pp. 105-110. Chicago, Mar. 1904. 

16. Troiu-Petersson, Gerda. Experimentelle versuch tlber die reifung und 

lochung des schwedischen gtlterkSses. Centialblatt ftkr Bakteriologie, Fuca- 
sitenkunde und Infektionskrankheiten, Abteilung 2, vol. 24, No. 13/15, p. 
343-360. Jena, Sept. 8, 1909. 

17. Van Sltkb, Lxtcius Lincoln, and Hart, Edwin Bret. The relation of carbon 

dioxide to proteolysis in the ripening of Cheddar cheese. New York Agricul- 
tural Experiment Station (State) Bulletin 231. Geneva, 1903. 



bnied September 9, ItlZ 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bullet m 153. 

A. D. MELVIN, r.Hi.h OP Bu.tnu. 



STUDIES ON THE BIOLOGY OF 
THE TEXAS-FEVER TICK. 

(SUPPLEMENTARY REPORT.) ^^ 



BV 
H. W. GRAYBILL, D. V. M., 

Assistant -Zoologist, Zoological Diidsioti, 
AND 

W. M. LEWALLEN, 

Agent ill Tick Eradication, Bureau of Atiimal Industry. 



WASHWCTON; 
GOVERNMKNT PBINTtNd OFFICE. 



BUREAU OF ANIMAL INDUSTRY, 



Chief: A. D. Melyin. 

Assistant Chief: A. M. Farrinoton. 

Chief Clerk: Charles C. Carroll. 

Animal Husbandry Division: George M. Rommel, chief. 

Biochemie Division: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsat, chief. 

Meat Inspection Division: Rice P. St^ddom, chief. 

Pathological Division: John R. Mohler, chief. 

Quuirantine Division: Richard W. Hickman, chief. 

Zoological Division: D. H. Ransom, chief. 

Experiment Station: E. C. Schroeder, superintendent. 

Editor: James M. Pickens. 

ZOOLOGICAL DIVISION. 

Chief: B. H. Ransom. 

Assistant Zoologists: Albert H ass all, Harry W. Gratbill, Maurice C. Hall, 
and Howard Crawley. 

Junior Zoologist' Winthrop D. Foster. 

2 



ADDITIONAL COPIES of this pubUoaUon 
J\. may b« procured from the Scr2BiNTEifi>- 
ENT or DociTMENTS, Oovernmcnt Printing 
Offloe Waahlngton, D. C, at 6 cents per copy. 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculttjbe, 

Bureau of Animal Industry, 
WashiTigUm, D. C, April 25, 1912. 

Sn^: In Bulletin 130 of this bureau there were reported the results 

of one year's investigations of the biology of the Texas-fever tick 

which were carried on during 1907 and 1908 at Auburn, Ala., by 

cooperation between the Alabama Polytechnic Institute and this 

bureau. The work was continued for another year, and I have the 

honor to transmit herewith a supplementary report by Dr. H. W. 

Graybill and Mr. W. M. Lewallen, giving the results of the second 

year's experiments (1908-9). As this information has a bearing on 

the cooperative work now being carried on by the bureau and the 

authorities of certain States for the eradication of the cattle tick, I 

recommend its publication as a bulletin of this bureau. 

Respectfully, 

A. D. Melvin, 

Chief of Bureau . 
Hon. James Wilson, 

Secretary of Agriculture, 



CONTENTS. 



Introduction 5 

Methods of study : 5 

Preoviposition period 6 

Ovipoeition period 6 

Incubation period 7 

Hatching period 8 

Longevity period 8 

Entire time of nonparasitic development 9 

Number of eggs laid and percentage hatched 10 

Comparison of results of indoor and outdoor experiments 10 

Appendix 18 

4 



STUDIES ON THE BIOLOGY OF THE TEXAS-FEVER TICK. 

(SUPPLEMENTARY REPORT.) 



INTRODUCTION. 

Dunng 1907-8 the Zoolc^cal Division of the Bureau of Animal 
Industry conducted a year's experiments on the life history of the 
Texas-fever tick at Auburn, Ala., in cooperation with the veterinary 
department of the Alabama Polytechnic Institute. The results 
obtained during the course of those investigations have been pub- 
lished in Bulletin 130 of the Bureau of Animal Industry. The work 
was continued for another year (1908-9) along the same but some- 
what less extensive lines. Mr. W. M. LewaUen, who assisted in the 
first year's work, had charge of the experiments during the second 
year. 

The second year's work was undertaken for the purpose of obtain- 
ing additional data on the nonparasitic periods in the life history of 
the tick, and to determine what variations might take place in the 
duration of these as a result of yearly variations in weather conditions. 

METHODS OP STUDY. 

The methods of study employed were the same as those used the 
first year. The indoor experiments were conducted by the use of 
incubation tubes, and these were checked by outdoor experiments 
conducted in field plots representing natural conditions. The incu- 
bation tubes used were the vertical type provided with a glass tube 
inserted into the bottom for the purpose of supplying the sand with 
moisture, shown in figure 1, Bulletin 130, Bureau of Animal Industry. 
The field plots were the same as those used in the first year's work 
(fig. 3, Bulletin 130), being 2 feet square. They were protected from 
the intrusion of small animals by means of a wire-netting fence. 

In the indoor experiments the ticks were handled the same as during 
the first year. Four engorged ticks were collected at the beginning 
of each month, and each was placed in a dish by itself, where it 
remained imtil oviposition was completed. At the end of every 24 
hours the eggs were removed from each tick, counted, and placed in 
an incubation tube marked with the nimiber assigned the tick and 
the date the eggs were removed. The dates when the eggs in each 
tube began and completed hatching, and when the first and last larvsB 



6 



BIOLOGY OP THE TEXAS-FEVER TICK. 



died, were recorded, and finally the per cent of eggs that hatched was 
determined. The indoor experiments were conducted in an miheated 
room, the windows of which were constantly open. 

In the outdoor experiments two sets of plots were run, one located 
in a place shaded a part of the day and the other in the sun. In each 
plot 10 engorged females were placed. 

PRBOVIPOSITION PERIOD. 

, The minimum preoviposition period noted was 2 days, which 
occurred in the case oi ticks collected in August. Ticks collected in 
August the first year had a minimum period of 2 days, but the mini- 
mum for the year (1 day) was observed in the case of a tick collected 
in April. The maximum period (29 days) was exhibited by ticks 
collected December 2, and the maximum for the first year (98 days) 
was observed in the case of a tick collected November 30. 

From the table Gsst column) it will be noted that the average pre- 
oviposition periods increase month by month from the minimum to 
the maximum, and then decrease again to the minimum. A similar 
increase and decrease were also shown in the case of averages for the 
first year's experiments in the horizontal tubes, but in the case of the 
ticks used for the vertical-tube experiments the averages for April 
and June were greater than for March. 

Preovipontion period— Range and average length of periods. 



Date ticks were 
collected. 



1908. 

Augusts 

September 1. 
October 1... 
November 2. 
December 2. 





Range of 


Average 


Number 


preoTl- 


ofpreovi- 


of ticks. 


positkm 


IMsltioii 




periods. 


periods. 




Dapa. 
2to 4 


Dapa, 
3 




3to 6 


4 




6 to 11 


7.8 




7to 9 


8.3 




17 to 20 


25.5 



Date ticks were 
collected. 


Number 
of ticks. 


Rangeof 
preovi- 
position 
periods. 


1009. 

January 1 

February 4 

March 1 




Dapa. 
22 to 24 

18 to 20 

9 to 16 

9 to 10 

8 


April 2 


July 2 





Average 
of preovi- 
position 
periods. 



Dapa, 
28 
10.3 
11.8 

0.8 

8 



OVIPOSITION PERIOD. 

The longest oviposition period noted was 82 days, observed in the 
case of a tick which began ovipositing in January. A tick in the first 
year's experiments which began to lay eggs in January had an ovi- 
position period of .91 days, but the longest period was exhibited by a 
tick which began ovipositing in November ai^d continued to lay eggs 
for 152 days. The second year the shortest period (7 days), as weU 
as the longest, occurred in January. The tick giving this period, 
however, deposited only 305 eggs, an exceptionally small number. 
The shortest period the first year was 3 days, and this occurred in June. 
The average oviposition periods for the first year increased month by 
month from a minimum in «lune to a maximum in November, and 



INCUBATION PERIOD. * 7 

gradually decreased again in the succeeding months. During the 
second year the same tendency was shown, the periods increasing 
from a minimum in August to a maximum in November, and then, 
following a sudden decrease for December, there was an increase for 
January and February, after which the decrease was regular for the 
remaining months. 

Oviposition period — Range and average length of periods. 



Month oviposl- 
tkm'began. 


Nnmber 
of ticks. 


Range 
of ovi- 
position 
periods. 


Average 
of ovi- 
position 
periods. 


Month oviposi- 
tion began. 


Nnmber 
of ticks. 


Range 

ofovi- 

position 

periods. 


Average 

ofovT- 

position 

periods. 


1006. 
August 


4 


Daps. 
13 to 16 
9tol8 
13 to 36 
66 to 63 
30 to 42 

7 to 82 


Daft. 
14.3 
14.8 
25.3 
69.5 
34.5 

46.8 


1909. 

February 

March 




Daft. 
37 to 69 
22 to 42 
26 to 32 
19 to 27 

11 to 19 

12 to 17 


Dofs. 
46.8 


September 

October 


88.3 


April 


29 


November 


May 


23.8 


Pewmber 


Jane 


16.8 




July 


U.8 


1909. 











INCUBATION PERIOD. 

The range of the incubation periods of the lots of eggs laid by each 
tick is given in the table in the Appendix. The range of the period 
for the second year was 18 to 176 days, as compared with 19 to 188 
days for the first year. In the table below only the periods from the 
time the eggs were deposited mitil the first eggs hatched in each lot 
have been used^ and these are referred to for convenience as the mini- 
mum incubation periods. The periods to the hatching of the last 
eggs in each lot have been included in the table in the Appendix. 
The longest minimum incubation period for both the first and the 
second year occurred in the case of lots of eggs deposited .during the 
month of October, being 173 days for the second year and 180 days 
for the first year. The shortest period for the second year was 18 
days and was observed in the case of lots of eggs deposited during 
the month of June, while the lots deposited during the same month 
of the first year gave a minimum period of 22 days. The shortest 
period for the first year (19 days) was furnished by lots of eggs depos- 
ited during the months of July and August. 

By comparing the averages in the table below it will be observed 
that they increase from August to October and decrease for the re- 
maining months, except in the case of the average for July, which 
shows a slight increase. In case of the averages for the first year it 
is noted that they increase for the months of August to October and 
decrease for the remaining months without interruption. 



8 • 



BIOLOGY OP THE TEXAS-FEVER TICK. 



Minimum incubation period — Range and average length of periods. 



Month <^gs de- 
posited. 



190B. 

August 

September. 

October 

November. 
December.. 

19D0. 
January..., 



Number 


Range of 


Average 


of lots. 


periods. 


of periods. 




Day*. 


n'-i 


52 


20to 30 


49 


32to 70 


44.8 


49 


141 to 173 


158.7 


66 


151 to 171 


157.5 


21 


139 to 158 


150.3 


70 


103 to 141 


121.6 



Month eggs de- 
posited. 



1909 
February 

March 

April 

May 

Jane 

July 



Number 


Range of 


of lots. 


periods. 




Dayt. 


48 


82 to 107 


170 


5Sto 90 


141 


38 to 65 


90 


26to 39 


47 


IS to 26 


51 


22 to 27 



Average 
of periods. 



Dayt. 
95.5 
71.5 
47.5 
30.6 
22.9 
24.5 



HATCHING PERIOD. 

The maximum hatching period for the second year was 52 days 
and for the first year 49 days, and in the case of both years this 
period belonged to a tick whose eggs began to hatch during the 
mqnth of October. The shortest hatching period for the second year 
was 6 days and occurred in the case of a tick whose eggs began to 
hatch in May, while for the first year the minimum period for the 
same month was 9 days. The shortest period during the first year 
(4 days) fell to the month of July. It is noted by referring to the 
averages in the table below that those for October and February are 
the same, and for the remaining months, with the exception of the 
break shown by May, there is a decrease, month by month, of the 
averages. In the firat year's work the averages increased from that 
for July to the maximum, which is for the month of October, and 
decreased for the remaining months, except for a slight increase for 
the month of June. 

Hatching period — Range and average length of periods. 



m 

Month hatching 
began. 


Number 
of ticks. 


Range of 
hatching 
periods. 


Average 
ofhatch- 

periods. 


Month hatching 
began. 


Number 
of ticks. 


Ranfeof 
hatcning 
I>6rlods. 


Average 
ofhatfSi- 

ing 
periixlB. 


1908. 
Aufust 


4 
4 

1 


Dayt, 
17 to 27 
47 to 52 

50 


Days. 
21.5 
50 

50 


1900. 
March 


2 
4 

20 
4 

8 


Day9. 
33 to 46 
18 to 21 
6to21 
12 to 18 
11 to 21 


Day*. 
39.5 


Ootober 


April 


19.3 




May 


13.8 


1909. 


^CJ 

June 


16 


Febn'ftiy 


July 


14.5 




1 





LONGEVITY PERIOD. 

The longest and shortest longevity periods obtained for the lots 
of larvse belonging to each tick are given in the table in the Appendix. 
The time to the death of the first larv» in each lot is referred to 
in the table below as the minimum longevity period and that to the 
death of the last larvse as the maximum longevity period. The 
longest maximum longevity period for the second year was 249 
days, as compared with 234 days for the first year, and both 



TIME OF NONPARASITIC DEVELOPMENT. 



occurred in the case of lots of eggs which began to hatch during 
the month of October. In referring to the averages it will be 
noted that there is no regular increase and decrease to and from 
the inaxiinum, and the same was noted in the case of the first 
year's experiments. This is no doubt due to the fact that tem- 
perature, while it plays some part, is not a controlling factor in 
the longevity of larv8B as it is in the case of the preoviposition, 
oviposition, hatching, and intubation periods. The range of the 
averages for the months of August to November of the second year 
is 104.5 to 213.7 days, whereas the range for the same months of the 
first year is 56.2 to 167.4 days. The range of the averages for the 
rest of the months of the second year is 63.3 to 77.6 days, as com- 
pared with a range of 38.6 to 73.2 for the remaining months of the 
first yeai:. 

Longevity period, — Range of maximum and minimum longevity and average o/maximtan 

longevity. 



Month lots 

began to 

hatch. 



1908. 
Aogust..... 
September. 
October.... 
November. 

1909. 
March. 



Num- 
ber 
of 
lots. 



6 
46 
31 
18 



30 



Range of 

Tnln imnm 

longevity 
peiiods. 



Dapt. 
16 to 36 

6 to 62 
13 to 165 
51 to 146 



lOto 42 



Range of 

longevity 
periods. 



Daft, 
99 to 192 
fi0to218 
80 to 249 
58 to 223 



10 to 112 



Average 
of max- 
imum 
longevity 
periods. 



Dav». 
121.8 
104.5 
213.7 
149.9 



71.6 



Month lots 

began to 

hatch. 



1909. 

AnrO 

May 

June 

July 

August.... 



Num- 
ber 
of 
lots. 



72 

355 

180 

56 

42 



Range of 
minimum 
longevity 

periods. 



2>ap9, 

6 to 60 

8 to 87 
7to85 

9 to 48 

7 to 47 



Range of 

longevity 
poiods. 



Davt. 
31 to 110 
14 to 119 
25 to 139 

9 to 106 
31 to 118 



Average 

of max- 
imum 
loiigey- 

periods. 



Poft. 
75.3 
77.6 
66.1 
63.3 
64.6 



ENTIRE TIME OF NONPARASITIC DEVELOPMENT. 

The entire time for each individual tick and its progeny, i. e., the 
time from dropping to the death of all the larvsB; is given in the table 
in the Appendix. The longest entire time during the second year 
(297 days J was obtained in the case of ticks collected September 1, 
while the longest period for the first year (288 days) occurred in 
the case of ticks collected October 1. The shortest period for the 
second year was 96 days and for the first year 79 days, and both 
occurred in the case of ticks collected the first part of June. The 
averages for the first year increase month by month from June to a 
maximum for October, and then decrease for the remaining months^ 
except that the averages for February and March are the same. 
The averages for the second year, given in the last column of the 
table below, do not increase to and decrease from the maximum 
without deviations, as do those for the first year. 



10 



BIOLOGY OF THE TEXAS-FEVEB TICK, 



Entire time ofnonparantic developtMnt. 



Date engorged 

females were 

collected. 


Numbei; 

of 
engorged 
females. 


Range of 

entire-time 

periods. 


Avenge 

of 
periods. 


Date engorged 

females were 

collected. 


Number 

of 
engorged 
females. 


Range of 

entire-time 

periods. 


Avenge 

of 
periods. 


1906. 
Augusts 


4 

4 
3 
4 
4 


DapB. 
143 to 254 
258 to 297 
271 to 280 
274to288 
257 to 268 


J>aM. 
200.6 
280 

279.3 

282 

264.8 


1909. 

January 1 

February 4 

March 1 




Dapt, 

202 to 253 
204 to 230 
185 to 207 

139 to 164 

140 to 185 
96 to 127 

110 to 149 


"Xi 


September 1.. <■.... 
October 1 


218.6 
196.8 


November 2 


April 2 


154 


December 2 


Mayl(7) 

June2(7) 

July 2 


156.6 
117 
129. HL 











NUMBER OF EGGS LAID AND PERCENTAGE HATCHED. 

During the second year the minimum number of eggs laid by a 
tick was 305 and the maximum 4,492. The average number of e^s 
laid by the various lots of ticks ranged from 1,885 to 4,262. The 
lowest percentage of eggs hatched was 3 per cent and the highest 
98 per cent. The percentage of eggs hatched in the case of ticks 
collected during December, January, and February ranged from 3 to 
60 per cent. For the first year the minimum number of eggs laid 
was 357 and the maximum number was 5,105, and the averages 
ranged from 1,811 to 4,089. The percentage of eggs hatched ranged 
from to 98 per cent. 

Egg laying and hatehing — Total and average number ofegge laid and per cent hatched. 



Date col- 
lected. 


Num- 
ber 
of 

ticlm. 


Number 

of eggs 

depooted. 


Ayerege 
number 
of eggs. 


Per oent 

of eggs 

hatched. 


Date col- 
lected. 


Num* 

ber 

of 

tickR. 


Number 
depcSted. 


Avenge 
number 
of eggs. 


Per oent 

of eggs 

hatched. 


1906. 
August 5. . . 
September 1 
October 1.. 
November 2 
December 2 




8,962 to 4,492 
2,797 to 3,654 
1,588 to 3,848 
2,215 to 3,329 
1,496 to 2,201 


4,262 
3,252 
2,768 
2,975 
1,885 


48 to 97 
92 to 98 
9to61 
62 to 71 
11 to 27 


1909. 
January 1.. 
February 4. 
March 1.... 

April2 

liayli 

June 2 < 

July 2 




a05 to 3,723 
1,993 to 2,970 
1,380 to 3,361 
1,741 to 3,065 
3, 181 to 4, 178 
1,640 to 3,003 
2,214 to 3,710 


2,615 
2,568 
2,352 
2,476 
8,674 
2,180 
2,948 
* 


StoOO 
11 to 41 
61 to 98 
86 to 96 
69 to 93 
60 to 97 
96 to 96 



1 Ticks were collected May 1 and 2. 



> Ticks were collected June 2, 3, 4, and 5. 



COMPARISON OF RESULTS OP INDOOR AND OUTDOOR 

EXPERIMENTS. 

In the next table the dates when the first eggs hatched and when 
all the larvae were dead in each month's experiments, indoors and 
outdoors, are given for purposes of comparison. These dates are of 
much practical importance in eradication work when rotation methods 
are employed, since the dates when the first eggs hatched are those on 
which ticky cattle placed on tick-free land on dates corresponding 
to those on which the experiments were begun will be in danger of 
reinfestation, and the dates on which all larvsB were dead are the 



COMPARISON OF RESULTS. 



11 



dates on which pastures from which all animals have been removed 

will be free of ticks. 

« 

Compariaon o/reoords of vertical tubes and field plots, Auburn^ Ala., 1908-9. 



Vertical tubes. 



Date females were collected. 



1908. 

Augusts 

September 1 

October 1 

November 2 

I>eoember2 

1909. 

January 1 

Febraar7 4 

Marohl 

April 2 

May 1-2 

June 2^ 

Jiily2 



Dateflzst 

agKs 
hatred. 



Aug. 30 
Oct. 7 
Feb. 25 
Apr. 22 
Mtay 11 



Ifay 19 
liay 21 

May 24 
Hay 28 

Jane 10 
July 2 
July 28 



Date all 
larvBB 
were 
dead. 



Apr. 16 
June 25 
July 8 
Aug. 17 
Aug. 27 



Sept. 11 
S^t 22 
Sept. 24 
Sept. 13 
Nov. 2 
Oct. 7 
Nov. 28 



Field plots. 



Date females were collected. 



I Date flzst 

eggs 
hatched. 



1908. 



August 5-6. . 
September 1. 
October 1... 
November 2. 



January 1. 
February 1-4. 

March 1-3 

April 2 

May 1-2 

June 2^ 

July 1-2 



1909. 



Aug. 31 
Nov. 23 
Apr. 19 
May 10 



May 21 
May 20 



10 

May 26 

June 12 
June 28 
July 26 



Date all 
larvsQ 
were 
dead. 



Apr. 8 

UAY 22 

June 23 

Do. 



July 30 
Aug. 6 
Aug. 25 
Sept 11 

Do. 
OcL 2 
Nov. 13 



In comparing the length of tune required fox tlie first eggs to hatch 
in the indoor and outdoor experiments it was found that for all the 
months except March, April, June, and July the time was longer in 
the outdoor than in the indoor experiments, the differences ranging 
from 1 to 53 days, and for the above-mentioned months the time was 
shorter, the differences ranging from 1 to 4 days. The longer time 
obtained in the majority of the outdoor experiments may be due in 
part to unavoidable errors in observation because of the fact that it 
is frequently difficult to determine with certainty when tlie first eggs 
hatch, since they are scattered and some may be hidden from view. 
In the first year's experiments practically the same results were 
obtained. For two of the eight months for which comparisons could 
be made the time was the same in the indoor and outdoor experi- 
ments, and for the remaining months the time was longer in the out- 
door experiments, the differences ranging from 1 to 22 days. 

In view of the fact that in the two years' experiments the time to 
the hatching of the first eggs was longer in the outdoor experiments 
than in the corresponding indoor experiments in all except four 
instances, in which cases the differences were comparatively small, 
ranging from 1 to 4 days, it seems safe to assume that indoor experi- 
ments, if the temperature is maintained near that on the outside, 
will be safe to follow in practical work, provided a reasonable margin 
of safety be allowed to cover slight variations that might occur in 
the direction of a shorter time for hatching. 

In the second year's work, for all months the time required for aU 
the larvae to die was longer in the indoor than in the outdoor experi- 
ments, the differences ranging from 2 to 55 days, and the average 



12 BIOLOGY OP THE TEXAS-FEVER TICK. 

difference being 28 days. In the first year's experiments similar 
results were obtaiaed; in all but one case the periods were longer in 
the indoor than the outdoor experiments, the differences ranging 
from 5 to 42 days, the average difference being 21 days. It there- 
fore appears that the time obtained indoors, with incubation tubes of 
the type employed, as a rule will be three to four weeks longer than 
that occurring under natural conditions. This is what would be 
expected, since ticks in tubes are not exposed to the wind, and when 
kept indoors are not subjected to the sun, in consequence of which 
they will not suffer the loss of body fluids and nourishment that ticks 
living in the open will. In addition to this, it is hkely that the 
humidity in the tubes as a rule is higher than that of the outside 
air, which would tend to prolong longevity of the larv». It is be- 
lieved that in using tubes such as were employed, the supply of 
moisture should not be excessive, the sand simply being kept moist. 
Unless this is done it is likely that the life of the larv» may be pro- 
longed far beyond that occurring under natural conditions. Unduly 
long periods for the death of all larvae, obtained by using incubation 
tubes, are safe but uneconomical, requiring the farmer to forego the 
use of his land longer than is necessary. It is important that the 
periods be ample, but it is likewise important that they be no more 
than this, since rotation methods are inconvenient and expensive at 
best in the majority of instances. 

In comparing the time required for all the larvsB to die for corre- 
sponding months in the indoor experiments for the two years it was 
found that for all but one month the time was longer the second year, 
the differences ranging from 3 to 45 days. The average difference 
was 25 days. A similar comparison of the outdoor experiments for 
the two years showed that in every instance the time was longer the 
second year, the differences rangiag from 2 to 36 days. The average 
difference was 17 days. 



APPENDIX. 



Individual records of ticks used in- experiments. 



Num- 
ber of 
tick. 



1.... 
2... 
3... 
4..., 

6... 

6... 

7... 

8... 

9... 
10... 
11... 
12... 
13... 
14... 
15... 
16... 
17... 
M... 
19... 
20... 



21.. 
22.. 
23.. 
24.. 
25.. 
26.. 
27.. 
28.. 
29.. 
30. . 
81.. 
32.. 
33.. 
34.. 
35.. 
36.. 
37.. 
38.. 
39.. 
40.. 
41.. 
42.. 
43.. 
44.. 
45.. 
46.. 
47.. 
48.. 



Date col- 
lected. 



1908. 

Aug. 5 
...do.... 
...do.... 
...do.... 

Sept. 1 
...do.... 
...do.... 
...do.... 

Oct. 1 

...do 

...do.... 
...do.... 

Nov. 2 
...do.... 

-._do 

...do 

Oec 2 

...do 

...do 

...do.... 



2 



1909. 
Jan. 

..do... 

.-do... 

..do... 

Feb. 

...do... 

..do... 
...do... 

Mar. 
...do... 
...do... 
...do... 

Apr. 

...do 

...do.... 
...do... 

Hay 1 

...do 

...do.... 
...do.... 

June 2* 
...do. 
...do. 
...do. 

July 
...do. 
...do. 
...do. 



2 



Num- 
ber of 
eggs de- 
posited. 



4,492 

3,962 

4,489 

4,104 

3,654 

3,604 

2,951' 

2,797 

1,588 

8,848 

2,730 

2,906 

3,187 

3,320 

3,167 

2,215 

1,858 

1,985 

2,201 

1,496 



3,723 
3,460 
2,970 
305 
2,601 
2,970 
2,706 
1,993 

1,674 
3,361 
1,380 
2,607 
8,065 
1,741 
2,401 
4,178 
4,040 
3,181 
3,296 
2.311 
3,003 
1,765 
1,640 
3,452 
3,710 
2,214 
2,416 



Preovl- 
podtion 
period. 



Dayt. 

8 

4 

3 

2 

3 

4 

4 

5 

11 

5 

7 

8 

7 

9 

8 

9 

28 

28 

17 

29 



24 
24 
22 
22 
19 
18 
20 
20 

9 
10 
12 
16 

9 
10 
10 
10 



3 
3 
3 
3 



Oviposi- 


Hatch- 


tion 


ing 


period. 


period. 


Dayt. 


Dayt. 


15 


27 


13 


17 


15 


24 


14 


18 


16 


52 


18 


51 


9 


47 


16 


50 


13 




35 


50 


20 


33 


33 


46 


63 


18 


66 


19 


58 


19 


61 


21 


31 


9 


35 


18 


42 


16 


30 


9 


82 


21 


48 


18 


46 


16 


7 


6 


40 


17 


42 


17 


59 


14 


37 


12 


41 


15 


28 


8 


42 


14 


22 


8 


26 


17 


32 


13 


27 


14 


31 


14 


27 


18 


25 


17 


24 


17 


19 


12 


19 


13 


11 


13 


15 


13 


18 


11 


15 


16 


17 


21 


12 


15 


15 


14 



Incubation 
period. 



Mini- 
mum 
lon- 
gevity. 



Dayt. 
20 to 

20 to 

21 to 
21 to 
32 to 
36 to 
31 to 
34 to 



36 
30 
34 
30 
73 
75 
71 
70 



141 to 176 
151 to 174 
146 to 174 

151 to 170 

152 to 168 
151 to 170 
143 to 160 

114 to 138 
103 to 142 
116 to 144 

115 to 139 



61 to 119 
73 to 120 
94 to 121 
111 to 117 
53to 87 
68 to 
49 to 
70 to 
45 to 
57 to 
44 to 
55 to 
86 to 
39 to 
39 to 
35 to 

26 to 

27 to 

28 to 
27 to 
18 to 

21 to 

22 to 

21 to 
24 to 

22 to 

23 to 
23 to 



97 
87 
90 
81 
84 
77 
77 
49 
50 
51 
48 
39 
37 
36 
41 
27 
27 
29 
27 
27 
27 
29 
28 



Dayt. 
15 
12 
17 
6 
58 
15 
21 
13 



10 
10 

7 
11 

6 
14 
18 
18 

8 
19 

8 



16 
16 
21 
49 
17 
21 

7 
28 
26 
14 
25 
25 
20 
23 
15 
11 
19 
17 
25 
14 
18 
20 
20 

9 
12 
13 
20 

7 



Maxi- 




mum 


Entire 


lon- 


time. 


gevity. 




Days. 


Dayt. 


116 


143 


218 


254 


141 


182 


207 


247 


249 


286 


237 


279 


222 


258 


249 


297 


100 


280 


87 


271 


112 


278 


107 


285 


98 


274 


110 


281 


106 


288 


100 


268 


97 


266 


100 


268 


87 


257 


104 


243 


113 


253 


103 


242 


64 


202 


98 


204 


114 


225 


111 


230 


106 


215 


116 


205 


107 


196 


97 


185 


119 


207 


106 


164 


95 


154 


101 


159 


81 


139 


118 


158 


96 


140 


100 


143 


139 


185 


80 


114 


95 


127 


62 


96 


84 


117 


118 


149 


94 


125 


81 


110 


106 

1 


134 



Percent 
hatched. 



48 
97 
61 
60 
98 
98 
93 
92 



19 

61 
52 
67 
59 
71 
27 
17 
15 
11 



60 
18 
17 
8 
33 
36 
41 
11 
79 
61 
93 
62 
94 
86 
94 
05 
03 
73 
85 
60 
97 
84 
60 
89 
08 
96 
96 
96 



1 Ticks were coliected May 1 and 2. 



* Ticlcs were collected June 2, 3, 4, and 5. 

13 



O 



21^ 



laued SeptembeilS. 1V12 

U. S. DEPARTME>JT OF AGRICULTURE. 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 153. 

THE ACTION OF ANTHELMINTICS '6NPA«A81fK ' 

LOCATED OUTSIDE OF THE 

ALIMENTARY CANAL. 



BRAYTON HOWARD RANSOM, 

Chief o/lhe Zoological IHj'isioit, 

AND 

MAUR[CE C. HALL, 

jissislnnl Zooloffisl, Zoological Division, 



THE BUREAU OF ANIMAL UTDUSTRY. 



Chief: A. D. Melvin. 

Assistant Chief: A. M. Fabbinoton. 

Chief Clerk: Chablbs G. Cabboll. 

AnSmal Husbandry Division: Geobge M. Rommel, chief. 

Biochetnic Division: M. Dobset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsat, chief. 

Meat Inspection Division: Rice P. Steddom, chief. 

Pathological Division: John R. Mohleb, chief. 

Quarantine Division: Richabd W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: E. G. Schboedeb, superintendent 

Editor: James M. Pickens. 

ZOOLOGICAL DIVISION. 

Chief: B. H. Ransom. 

Assistant Zoologists: Albebt Hassall, Habby W. Gbaybill, Maubice G. 
ttat.t., and Howabd Gbawley. 
Junior Zoologist: Winthbop D. Fostek. 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

Bureau of Animal Industry, 
Washington, D. C.^ May 2, 1912. 
Sir: I have the honor to transmit herewith, and to recommend for 
publication as a bulletin of this bureau, a manuscript entitled " The 
Action of Anthelmintics on Parasites Located Outside of the Ali- 
mentary Canal," by Dr. B. H. Ransom, Chief of the Zoological Divi- 
sion, and Mr. Maurice C. Hall, assistant zoologist in the Zoological 
Division of this bureau. 

This paper details the results of some attempted medicinal treat- 
ment of sheep for tapeworm disease, and also summarizes our knowl- 
edge of the use of anthelmintics against parasites located outside 
of the intestinal lumen. While the experimental results were nega- 
tive, the evidence brought together here indicates the need of further 
work, and this paper is intended to simplify additional work by 
furnishing a systematic summary of all previous work. It also has 
immediate practical utility as an aid in judging the claims made for 
proprietary medicines. 

Very respectfully, A. D. Melvin, 

Chief of Bureavr. 

Hon. James Wilson, 

Secretary of Agriculture. 

8 



CONTENTS 



Pagv. 

Introductory 5 

Historical review 6 

Somatic and extraintefltinal t^niasis 6 

Dlstomatiasis 10 

Authors' experiments - 16 

General summary and criticism - 19 

Bibliography 20 



THE ACTION OF ANTHELMINTICS ON PARASITES LOCATED 
OUTSIDE OF THE ALIMENTARY CANAL. 



INTRODUCTORY. 

As Gommonly employed, the remedies known as anthelmintics are 
usually efficacious preparations. Their action is based on the prem- 
ises that they are poisons which can be taken into the digestive tract 
of such animals as man, the horse, dog, or cat, in quantities not large 
enough to poison the host but sufficient to stupefy or kill verminous 
parasites with which they come in contact. The parasites are usually 
in the small intestine (intestinal helminthiasis) and occasionally in 
the stomach (gastric helminthiasis). In order to avoid dilution of 
the medicine, and alsK> to give a more effective contact with the para- 
site, the patient is prepared in advance by fasting to empty the 
stomach and intestine. Finally a purgative is administered to carry 
out the dead or stupefied worms. All this is comparatively simple 
and in practice effective. 

Though anthelmintics may be used very successfully in treatment 
for parasites in the stomach and small intestine of certain animals, 
they are, as a rule, less satisfactory when applied to ruminants. Medi- 
cines administered to ruminants must first pass the first, second, and 
third stomachs, some or all of which are usually well filled with food 
and difficult to empty in any reasonable period of fasting, before 
reaching the usual location of gastric parasites, the fourth stomach, 
through which in turn the medicines must pass before they reach 
the small intestine. In some cases, however, gastric and intestinal 
helminthiasis in ruminants may be treated successfully. Perroncito 
(1885)* and Stiles (1902), for example, have reported satisfactory 
results from the use of various remedies for stomach worms of sheep. 
Certain experiments have indicated that under the right conditions 
remedies may pass dire<itly through the first stomach and thus arrive 
more or less promptly in the second and following stomachs and the 
intestine. Powers (1909), however, has questioned this, and con- 
siders medicinal treatment for stomach worms in ruminants unsat- 
isfactory. 

As to the treatment of parasites located in the large intestine, it 
has been found in actual practice, even in animals with simple 

^ References to literature will be found In bibliography at end of bulletin. 

5 



6 ACTION OP ANTHELMINTICS ON PARASITES. 

st<Hnachs and short alimentary tracts, such as the dog, that the results 
from the administration of remedies per orem are generally very 
unsatisfactory. Stiles and Pfender (1902), for instance, found that 
thymol, a classic remedy for hookworms, was without effect on whip- 
worms of the cecum of the dog. On the other hand, Miller (1904:) 
claims to have succeeded in removing whipworms from the dog by 
the use of oleoresin of male fern. Parasites located in the large 
intestine are, however, difficult to reach with ordinary anthelmintics 
administered by mouth. 

In view of the difficulty of reaching parasites located in the ali- 
mentary tract beyond the stomach or small intestine, or even in these 
organs in ruminants, by means of anthelmintics administered through 
the mouth, it would seem on first thought that treatment with such 
remedies for worms in the liver, pancreas, muscles, brain, blood, or in 
other locations outside the direct course of the digestive tract, would 
be certain to result unsuccessfully. Nevertheless several more or less 
commonly used anthelmintics have received favorable consideration' 
in the treatment of verminous parasites located outside the lumen of 
the stomach and intestine, and the results of the tests made in some 
cases apparently afford a basis for a belief in their efficacy. 

HISTORICAL RSVISW. 

A consideration of the work done on this subject shows that 
writers, in general, have recognized two lines of work: First, the 
treatment of somatic and extraintestinal tseniasis where parasites 
are located in the brain, muscles, liver, or subcutaneous tissue; and 
second, the treatment of certain forms of distomatiasis, where the 
parasites are located in the liver or blood. Parasites in the liver are, 
of course, relatively nearer the usual site of operation of anthel- 
mintics. To the first line of work we wish to add some notes on the 
treatment of tseniasis where the parasites are located in the liver and 
in the pancreatic and bile ducts. In this case the parasite, Thysano- 
soma actinioidea^ is also an intestinal parasite, and we use, therefore, 
the terms extraintestinal and intestinal thysanosomiasis to indicate 
the two forms of infestation with the adult worm. 

Since writers along either of the two lines mentioned have usually 
confined their abstracts and criticism of related work to work along 
the one line, this review will summarize the two lines of work 
separately. 

SOMATIC AND EXTRAINTESTINAL TJENIASIS. 

Ztirn (1882a) states that after trying for 24 years to find some 
medication that would cure gid in sheep, he has concluded that suc- 
cessful treatment of the sort is impossible, and cautions against the 
administration of poisons, which, in his opinion, results in nothing 



HISTORICAL REVIEW. 7 

but a waste of time and money. It is unfortunate that he did not 
give his experiments in detail, or at least name the * remedies he 
tried ; but from the fact that he speaks of them as poisons it seems 
reasonable to suppose that he tested the various common anthelmin- 
tics, all of which are poisons* 

Curtice (1889a and 1890c) records tests of various remedies in 
intestinal and extraintestinal thysanosomiasis of sheep, and says: 

Various tonlafuges were tried with little succesa The jwwdered pr^wira- 
tlons of pumpkin seed, pomegranate-root bark, koosoo, kamala, male fern, and 
worm seed proved of no avail. • ♦ ♦ The presence of tcenlsB in the biliary 
ducts is another reason why tsenlafuges can not be entirely successful in treatr 
ment of sheep with T, fimbriata [Th, acftinioidea]. Any medicine which would 
affect the tsenlse in these ducts would also affect the sheep seriously. It is 
doubtful whether they can be killed or driven from the ducts. 

Feletti (lS94c) administered ethereal extract of male fern in three 
cases of human cysticercosis, as follows : 

1. Patient had had TttrUa 8oUum. Present symptoms: Convulsions, cepha- 
lalgia, vertigo, vomiting. Small subcutaneous nodules appeared and grew to 
the size of olives; one of these was excised and found to be CysHcerctis celln- 
lo8W. No cestodc proglottids or eggs were found on fecal examination. Feletti 
administered 1 f o 3 grams of extract of male fern -per diem to the patient until 
he had given 18 grams. The patient could not stand more. The cystlcerci 
diminished to the size of a wheat grain, but the cerebral trouble did not im- 
prove, and the man died a month later. No autopsy was permitted. 

2. Patient had 34 subcutaneous nodules. One of these was excised and found 
to be CysHcercus celluloscB. No cestode proglottids or eggs found on fecal 
examination. Feletti at first administered 1 to 1.5 grams of extract of male 
fern per diem, but this was not supported and the dose was accordingly cut 
down to 40 centigrams The total amount administered was 26.5 grams. Tbe 
nodules diminished untU they could not be felt 

3. Patient had had a tapeworm three years before and had not recovered 
the head in several attempts at removal. Present symptoms: Ck)nvulsioDflp 
vertigo, and vomiting. For this he was treated with sodium and potassium 
bromid. Seven nodules developed. One of these was excised and found to 
be a cystlcercus. Feletti administered 60 centigrams of extract of male fiera 
per diem, and in a month the nodules had disappeared. The nervous condition 
was improved, but the trouble subsequently recurred and was treated with 
bromids with good results. Feletti thinks the recurrence was due to brain 
alterations, but considers that the cystlcerci were dead. 

According to Feletti, these cases demonstrate that extract of male 
fern kills subcutaneous and muscular cystlcerci and that it probably 
acts upon cerebral cystlcerci also. He advises a dose of 30 to 40 
centigrams per diem for 30 or 40 days. 

De Benzi (1908) renewed the interest in this line of work by his 
report of the administration of extract of male fern in four cases of 
human somatic tseniasis. We quote the following abstract of Do 
Renzi's cases from Hall (1909) : 

1. The patient had occasion to eat badly cooked pork and uncooked sausage; 
had an infection with Tamia solintm five years previous; had attacks of con* 



8 ACTION OF ANTHELMINTICS ON PARASITES. 

TUlslons and insensibility three years later, and on treatment with a vermifnge 
had passed a tapeworm with the head. Two months later the patient had 
stronger convulsions, dizziness, and shortness of breath on slight exertion. 
About this time growths appeared on the temples and the stemocleido- 
mastoideus. Five months later the patient had three cramp-like attacks in 
one day, followed by great exhaustion. At this time the patient came to De 
Benzi, who found small swellings over the entire body and great nervous de- 
pression. On the history given here he diagnosed cysticercus of the brain and 
sktn. After a year's ambulant treatment with male fern the nervous trouble 
liad disappeared, so had the swellings, with the exception of one over the left 
temple, and this was removed by operation and showed the presence of a 
cysticercus. The eosinophilla present at the beginning of the treatment had 
disappeared. 

2. The second patient, a woman, had an infection with Tcpnia solium three 
years before. For two years previous to treutmait she had suffered from 
dizziness, headache, weak memory, polyuria, and weakness. A swelling over 
the manubrium steml showed all the characteristics of a cysticercus. After a 
week's treatment the nervous symptoms had disappeared and the swelling was 
reduced to one-third its original volume. A microscopic examination of the 
swelling was made, but De Renzl states that in this examination nothing of 
special importance was noted. 

3. In De BenzVs third case there was a history of increasing pain in the 
hypochondrium for 20 months, no fever or emaciation, increase in the area of 
liver dullness, eosinophilla present, urine normal. The case was diagnosed as 
hepatic echinococcosis, and all symptoms disappeared under treatment In 20 
days. • • • Fecal examination did not show parasites or their eggs. 

4. The fourth patient was a woman who had suffered for a year with a pain 
in the thorax and often coughed blood. In the absence of tubercular symptoms 
and because the patient coughed up membranes, " H&utchen,'* a diagnosis of 
lung echinococcosis was made by De Renzl and confirmed by two associates. 
In the brief period of six days she was cured by male fern. 

Dianoux (1909) has recorded a case in which ocular and subcu- 
taneous cysticercosis, possibly complicated by cerebral cysticercosis, 
was apparently cured by the administration of male fern. 

Before coming under Dlanoux's care, March 25, the patient had had several 
epileptiform attacks, and had nearly lost the sight of the left eye. Examination 
with the ophthalmoscope showed the presence of a cysticercus in the vitreous 
humor, and some weeks later a nodule, presumably a cysticercus, was found 
beneath the skin of the groin. After treatment with male fern and calomel the 
patient passed 4 or 5 meters of tapeworm {Tcenia solium). Hay 2 the patient 
experienced an eplleptifoim convulsion. From May 3 to 20 the patient took 2 
grams of extract of male fern per day; treatment was then suspended a few 
days. On May 24 a slight epileptiform attack occurred. Examination with the 
ophthalmoscope showed that the cysticercus had become shriveled and motion- 
less. From May 25 to June 5, 2 grams of extract of male fern per day were 
administered. June 12 the cyst in the groin was discovered. June 16 an epi- 
leptiform attack occurred, lasting 15 minutes, and the following day there was 
another attack. Treatment was resumed. July 2 treatment was suspended; 
the cyst had disappeared from the groin ; the general health of the patient was 
excellent. During 10 days in August the patient was given 1.5 grams of extract 
of male fern per day. November 15 the patient was discharged as cured. The 
cysticercus had entirely disappeared from the eye. The only evidence of its 
former presence was a cicatrice and vascular condition of the retina at the 



HISTOBICAL REVIEW. 9 

point where the parasite had been located. Altogether 102 grams of extract of 
male fern had been admlDlstered during a period of 71 days, and presumably 
as a result of this treatment a cysticercus of the eye, one under the skin of the 
groin, and probably others in the motor centers of the brain, had degenerated 
and become absorbed. Dianoux concludes that male fern destroys cysticercl 
because of some selective action against these parasites. 

Kailliet in his abstract of De Renzi's article (De Renzi, 1909) has 
noted that it would be interesting to test male fern on domestic 
animals suffering from parasitic diseases of the muscles and viscera, 
and mentions gid as one disease in which this treatment should be 
attempted. Such treatment was attempted and reported by Hall 
(1909). The treatment was tried on three sheep as follows: ^ 

1. Sheep showed characteristic symptoms of gid. Fifty grams of male fern 
powder administered on two consecutive days. The third day the attendant 
accidentally got the dose in the windpipe of the sheep, killing the animal. 
Post-mortem examination showed a large living coenurus in the cerebrum. t 

2. Sheep showed pronounced symptoms of gid. Ethereal extract of male 
fern administered in 5 c. c. doses on 27 days between April 22 and May 30, a 
total of 135 c. q. Sheep found dead May 30, following a gradual increase in 
anfavorable symptoms from May 1. Post-mortem examination showed a large 
living coenurus In the cerebrum. 

3. Sheep showed characteristic symptoms of gid. Ethereal extract of male 
fern administered in 5 c. c. doses on consecutive days, with the exception of 
one day, until a total of 45 c. c. had been given. No Improvement in condi- 
tion. Treatment discontinued and sheep found dead four days later. Post- 
mortem examination of the brain showed a small live coenurus. 

Hall has given a critical review of De Renzi's cases, and concludes 
that they are open to suspicion of error as regards diagnosis and the 
connection between the disease, the treatment, and the cure. 

Moussu (1910) has also reported some tests of ethereal extract of 
male fem administered for two months to two giddy sheep. There 
was a marked amelioration of symptoms, but at the autopsy, two 
months after the cessation of treatment, there was a coenurus in the 
brain of each, very large in one case and the size of a hazelnut in 
the other, and neither of them degenerated. Moussu also tested the 
treatment on a pig affected with cysticercosis which had been devel- 
oping for more than six months, the vesicles being readily visible 
under the tongue and the conjunctiva. The condition of the pig, 
instead of improving, became worse from day to day. 

In view of the conflict between his results and those obtained by 
De Renzi and Dianoux, Moussu concludes that the influence of male 
fem only makes itself felt on young lesions and those in course of 
development, but that where the cysts are entirely developed the 
medicament remains entirely without effect. 

The most recent published work upon this subject available to us 
is that of D6v6 (1911). His test of the treatment was as follows: 

Three rabbits were given a subcutaneous injection of brood capsules from a 
hydatid cyst. No. 1 was liept as a checlc. No. 2 was given each day for 52 

50664**— Bull. 153—12 2 



10 ACTION OP ANTHELMINTICS ON PARASITES. 

days 4^ c. c. of ethereal extract of male fern. The weight of the rabbit was 
2.9 grams. No. 3, weighing the same, was given 9 c. c, or 6 c. c. per kilogram, 
or double the corresponding dose for man. The treatment was begun the same 
day as the injection. ' Five months later normal live echinococcus cysts were 
found in all three rabbits. From this D4v4 concludes that in doses as large 
or twice as large as De Renzi used and extending over a much greater length 
of time the male fern was without effect on the hydatid cysta The treatment 
showed itself incapable of affecting the delicate metamorphosis of the scolex, 
an initial phase in which it seems that the parasite would be especially vul- 
nerable. Male fern is therefore provisionally deemed inefficacious In hydatid 
disease. 

Deve notes that his results in echinococcosis are in agreement 
with the negative results obtained by Hall in cysticercosis (Dave's 
error; Hall's cases dealt with ccenurus, as noted above), by Moussu 
in coenurosis, and finally with the very unsatisfactory results ob- 
tained by Railliet, Moussu, and Henry in distomatiasis. 

A summary of the foregoing indicates that results following the 
administration of male fern were claimed as follows : 

Successful in 6 cases of human cysticercosis (4 subcutaneous, 1 
subcutaneous and cerebral, and 1 subcutaneous and ocular) , and in 2 
cases of human echinococcosis (1 hepatic and 1 pulmonary) ; a total 
of 8 cases of human somatic taeniasis. 

Unsuccessful in 5 cases of ovine cerebral coenurosis, 2 cases of 
leporine general echinococcosis, and 1 case of porcine muscular and 
ocular cysticercosis; a total of 8 cases of somatic tajniasis in lower 
animals. 

A critical discussion of these cases will be given later. It is suffi- 
cient at this point to note that all tests on man were claimed to be 
successful and that all experiments on animals were failures. The 
cases of Zilrn and Curtice are too indefinite to include in this sum- 
mary. 

DISTOMATIASIS. 

I 

Under this heading hepatic distomatiasis will be considered first 
and venal distomatiasis second. ^ 

Grassi and Calandruccio (1884 and 1885) record the first cases of 
which we are aware where extract of male fern was used in dis- 
tomatiasis. The article published in 1884 is not available to u^, 
but from the article of the following year it appears that they ad- 
ministered to sheep a single dose consisting of 5 grams of ethereal 
extract of male fern in 50 grams of ethereal tincture of male fern^ 
They note that one might use injections of male fern, but that ii 
would not always be necessarJ^ The injection should consist of l| 
gram of the ethereal extract mixed with 1 gram of the tincture and] 
injected directly into the liver by means of a Pravaz syringe. A 
postscript, based on later work, adds that this injection should not 



HISTORICAL REVIEW. 11 

be employed- They find that for 24 to 48 hours after the adminis- 
tration of the medicine the feces contained numerous flukes and 
nmnatodes. After three days the feces show no eggs, and on autopsy 
no flukes or strongyles are found. The number of tests and other 
details are not given. 

They point out that this remedy should be tried in human dis- 
tomatiasis, and that the injection method might be useful in echino- 
coccus infections. 

Perroncito (1886) has repeated the experiments of Grassi and 
Calandruccio and reports favorably on the use of male fern, noting, 
however, certain unfavorable results from its use. His experiments 
were as follows; 

1. Sheep with symptoms of fluke disease. Fecal examination sliowed two 
to three eggs of Btrongylus, probably 8, oantortus, and three to four fluke eggs 
per slide. Administered 10 grams of ethereal extract of male f^m in 48 grams 
of ethereal tincture. The animal became tympanic, due to ethereal vapor de- 
veloped in the stomach, and in a few minutes fell as if struck dead. After 40 
minutes rose. At the end of 2 hours it had recovered from the symptoms of 
anesthesia and other phenomena of etherization. Some weeks later the feces 
showed one strongyle egg and one dlstome egg per slide. 

2. Administered to sheep affected with liver fluke, 5 grams of ethereal extract 
of male fern in 50 grams of the tincture. Usual symptoms of flatulence and 
defecation. After 30 to 40 minutes sheep gradually returned to normal condi- 
tion. Examination of the feces showed numerous dlstome and strongyle eggs. 
Two days later examination showed dlstome and hookworm eggs, but notice- 
ably diminished in number. There had been 10 to 12 eggs per slide ; there were 
now 4 to 5. 

Two days later repeated the dose, substituting 6 grams of ethereal extract 
In place of 5 grams. The animal showed more severe symptoms than on the 
first occasion. There was considerable flatulence at the end of an hour. 

Feces collected 40 hours after the second dose of male fern showed 2 to 3 
dlstome ^gs per slide. Animal seemed much improved. Seven days after the 
second dose the faces showed only one dlstome egg to three or four slides. 

3. A aheep infested with a large number of liver flukes» about 800, was given 
a large dose of male fern and died in 10 or 12 hours. Aufopsy showed that 
the flukes were apparently all dead. 

This last case had been previously published by Perronci^ (1885). 

The next article dealing with experimental medication of hepatic 
distomatiasis which has come to our attentioh is that of Bomagnoli 
(1903), who claims to have had good results in the treatment of dis- 
tomatiasis in sheep from the daily administration of 1 grain of salol 
in a teaspoonful of water for 8 days. According to that author the 
salol kills the cercariee which are still in the stomach and thus pre- 
vents further infestation, so that if the sheep are meanwhile given 
plenty of nourishment they rapidly recover their health and finally 
become completely cured. Eomagnoli's treatment is of a different 
character from that reported by other writers in that it is supposed 



12 ACTION OF ANTHELMINTICS ON PAKASITES. 

to act upon parasites during their invasion of the body and not upon 
those which have already become established in the host 

Floris (1907, 1908) has used carbon bisulphid, a remedy which 
Perroncito and Bosso (1894) and Wessel (1901) had reported as 
efficacious against Gastropkilus in the horse, and whidi Taar (1907) 
had found efficacious against Gastropkilus and Ascaris in the horse. 
Floris administered the carbon bisulphid in gelatin capsules in doses 
of 10 to 15 grams three or four times a week. The treatment was not 
attended by unpleasant effects and served to free the animals of 
flukes, the feces containing 5 to 10 flukes at a time. Floris notes that 
this is a very inexpensive remedy. 

Alessandrini (1908) reports that he had administered extract of 
male fern to two sheep which were severely infested. The sheep were 
dead two days later. Autopsy showed the flukes in the intestine and 
liver to be dead and degenerated. 

Pericaud (1908) has a rather glowing account of the virtues of a 
so-called " distomasine," said to consist of a glucosid and some plant 
essence. He gives no experimental tests, and the paper apparently 
adds nothing to our knowledge 

Borini (1911) states that in 1905, at the suggestion of Perroncito, 
ethereal extract of male fern was used to arrest a plague of bovine 
distomatiasis occurring on the estate of a rich proprietor in Calabria. 
Experiments have been made on laboratory animals from that year 
on, the treatment being especially tested on sheep. These experi- 
ments, according to Borini, confirm the therapeutic value of male 
fern against distomatiasis. In light infections cures were always 
obtained; in the worst cases of advanced cachexia the treatment 
failed. The use of thvmol in connection with male fern is recom- 
mended. < 

Railliet, Moussu, and Henry (1911) have recently published a 
series of articles on the treatment of distomatiasis. In their first 
papers (1911a and 1911b) they note the desirability of some medica- 
tion in view of the considerable losses suffered in France in 1910. 
They first experimented with medicines which may be eliminated 
by the liver, especially filoes, calomel, sodium salicylate, and "boldo." 
Most of the animals treated with these remedies improved, but there 
was no cure, no destruction of the parasites. Autopsy showed the 
flukes to be still alive after treatment extending over 15 days to 
three weeks. It seemed as though the trefatment reduced the activity 
of the flukes without really having a specific effect on them. 

In another series of experiments they used compounds of phos- 
phorus, arsenic, and mercurj^, as phosphorated oil, arsenic, atoxyl, 
arseno-benzol, trypanblau, benzoate of mercury, and fluid extract of 
broom. None of them gave certain, positive results. 



HISTORICAL REVIEW. 13 

In a third paper (Railliet, Moussu, and Henry^ 1911c) these 
authors report better success in their tests of a new series of sub- 
stances, including particularly tartar emetic, urotropin, atoxyl, and 
ethereal extract of male fern. 

The sheep used were for the most part heavily infested and had 
an intense cirrhosis and often a perforation of the capsule of Glis- 
son, the flukes which caused the perforation escaping to the peri- 
toneal cavity. Many had admixed infection with Fasciola hepatica 
and Dicrocodium lanceatum. 

Tartar emetic and urotropin proved to be inefficacious. Atoxyl 
produced the evacuation of degenerated F. hepatica in one heifer. 

The tests with ethereal extract of male fern were more satisfac- 
tory. An abstract is given of Alessandrini's (1908) experiments with 
male fern, noting this as the only work of the sort of which they 
were aware. Their own teste were made on five sheep, three others 
being kept as checks. The sheep were given 5 grams of ethereal 
extract in 25 c c. of oil. Autopsy was made immediately after 
death. The experiments are as follows : 

1. Sheep received one dose and died 12 hours later. Three hundred and 
ninety F. hepatica and numerous D. lanceatum in liver ; all alive. 

2. Sheep received two doses at 16-hour intervals and was killed In extremis 
24 hours after the second dose. The biliary canals contained numerous live 
D, lanceatum and 55 F. hepatica, 4 of them being alive and the rest degen- 
erated and of a yellowish-green color. The gall bladder contained 142 F. 
hepatica, all dead, though only 3 showed the same alteration as the preceding. 
The small intestine contained 16 degenerated specimens and the large intestine 
contained 10 dead but not degenerated specimens. 

3. Sheep received three doses at 16 and 24 hour intervals. Killed 3 days 
after the last dose. Biliary canals contained several live Z). lanceatum. 
There were 9 F. hepatica, all degenerated, in the gall bladder, but none in the 
biliary canals or in the Intestine. 

4. Sheep received four doses at 24, 24, and 48 hour intervals. Died 7 hours 
after the last dose. Biliary canals contained numerous live D. lanceatum. 
There were 5 degenerated F. hepatica in the gall bladder, none in the biliary 
canal, 1 degenerated specimen in the large intestine, and about 50 live speci- 
mens in the peritoneal cavity, associated with peritonitis. 

5. Sheep received four doses at 48, 24, and 24 hour intervals. Killed 3 days 
after the last dose. Biliary canals contained sevefal D. lanceatum, all living. 
There were no F. hepatica in the bile ducts, the gall bladder, or the intestine. 

The three check sheep were killed at the end of the experiment and showed 
178, 85, and 497 F. hepatica, respectively, and numerous D. lanceatum, aU 
living. 

The degeneration undergone by F. hepatica under the influence of male 
fern, and to a lesser extent of atoxyl, begins at the posterior extremity and 
progresses anteriorly, spme individuals being green and flabby at the i)osterior 
end, while the cephalic end was still capable of movement 

They conclude that male fern is a satisfactory treatment for in- 
fection with F. hepatica if takeil before there are irremediable 
lesions and at least four doses of 5 grams each administered. This 



14 ACTION OF ANTHELMINTICS ON PAKASITBS. 

will kill F, hepatica in the liver, but not in the peritoneal cavity. 
At the same time it is effective against gastrointestinal strongylosis. 
It has no effect on D. lanceatum. 

In a later paper (Railliet, Moussu, and Henry, 1911d) these 
authors recapitulate the foregoing, noting the earlier work of 
Grassi and Calandruccio and of Perroncito. They add the following 
experiments: 

Four sheep were given 5 grams of ethereal extract of male fern in 25 c. c. of 
oil for four successive days, a fifth animal being kept as check. All the sheep 
showed fluke eggs in the feces. Four days after the last dose they were all 
killed. Autopsy showed the following: 

1. Liver contained 1 F. hepatica (presumably alive), but marked lesions of 
cirrhosis indicated the recent disappearance of other flukes. 

2. Liver contained 2 live F, hepatica in the terminal ducts and 3 dead 
and degenerated forms. Hepatic lesions moderated. 

3. Liver, abnormal in appearance, contained 26 live F. hepatica and 1 
dead one. 

4. Liver contained 1 live F, hepatica. 

5. Check animal. Liver strongly cirrhotic, contained 296 live F. hepatica. 
All animals contained a number of live D. lanceatum. 

They conclude that male fern is effective, and, for sheep, suggest 
a dose of 1 gram of ethereal extract for every 5 kilos of live weight of 
animal ; for cattle, about 30 grams for 350 to 400 kilos of live weight. 
They note that male fern is comparatively cheap and suggest that it 
be administered by means of a rubber tube. 

The status of anthelmintics in bilharziasis is indicated in the 
following summary : 

Stiles (1904) says: "Favorable results are claimed from repeated 
doses of male fern ; some authors consider specific treatment futile." 

Sandwith (1909) writes of bilharziasis: 

No method has as yet been discovered of killing the worms in the human 
body; the ordinary vermifuges are uselesa ♦ • ♦ The liquid extract of 
male fern, in doses of 15 minims 3 times a day, is the only drug of known value, 
for, though it does not expel the parasites [How could it?], it seems to weaken 
their power of doing harm; it diminishes hematuria, allays vesical Irritation, 
and reduces the number of eggs passed in the urine and feces. 

Joannid&s (1911) has tried salvarsan in bilharziasis in 8 cases, and 
reports that a single injection of 0.5 to 0.6 gram (?) of salvarsan 
in the case of adults and 0.25 gram (?) in the case of a 12-year-old 
child resulted in cessation or great diminution of hematuria, relief 
from vesical and urethral irritation, and a disappearance of the eggs 
from the urine. He concludes that salvarsan is destructive of Schis- 
tosomum hoem-atohium and its eggs and thus brin^ about a cure of 
the disease. 

Loos-s (1912) takes exception to the conclusions of Joannidte and 
states that bilharziasis is a disease characterized by lesions due to the 
passage through or retention in the tissues of the bladder, rectum, 



HISTOBICAL BEVIBW. 15 

etc., of vast numbers of eggs, the parasite itself in the blood vessels 
having practically no direct pathological significance. By the time 
the patient goes to a physician for treatment for hematuria the 
worms producing the ^gs which cause this are probably dead or 
near their end. Looss looks upon the cures reported by Joannid^s 
as resulting from an artificial retention of the eggs in the tissues, 
causing thereby a suppression of the symptoms but not a cure of the " 
disease. For the purpose of this article — a consideration of the 
question whether anthelmintics are effective against metazoan para- 
sites located elsewhere than in the digestive tract — ^the question as to 
whether the killing of the fluke is desirable or not, or as to whether 
the bilharzia disease is, strictly speaking, one due to flukes or to 
fluke eggs, is not material. Looss does not attack Joannid^'s con* 
elusions that the embryos in the fluke eggs and possibly the adult 
flukes, also, are killed by salvarsan. 

Conor (1911) has tried salvarsan in one case of bilharziasis and 
found it inefficacious. Eggs containing living miracidia were found 
in the patient's urine every day but one for a month after the 
treaiment. 

Fiillebom and Werner (1912) have also tried salvarsan in a case 
of bilharziasis. with the same negative result. 

Day and Richards (1912) have criticized Joannides's findings, and 
report three cases in which salvarsan was administered with no effect 
on the passage of living ova or, in two cases examined, on the 
eosinophilia. 

A summary of the foregoing papers on the treatment of hepatic 
distomatiasis shows the following: 

The administration of anthelmintics has been declared effective by 
Grassi and Calandruccio as a result of experiments (number not 
given) followed by fecal examination and post-mortem (inale fern) ; 
by Perroncito after three experiment cases followed by fecal ex- 
amination and post-mortem (male fern) ; by Floris after experiments 
(number not given) in which no autopsies or subsequent fecal ex- 
aminations showing absence of eggs are noted (carbon bisulphid) ; 
by Alessandrini after two experiment cases followed by autopsy 
(male fern) ; by Borini after experiments (number not given) in 
which no autopsies or subsequent fecal examinations showing absence 
of eggs are noted (male fern and thymol) ; and by Railliet, Moussu, 
and Henry after nine experiment cases, four other animals being 
used as checks, followed by autopsy (male fern). This is a total of 
14 detailed experiments and 2 other sets of tests with the number of 
animals not given. Eomagnoli's treatment is omitted from con- 
sideration in this summary, as no claim has been made that it affects 
parasites already established in the host. 

. In the case of venal distomatiasis, male fern has been commended 
as being efficacious, with no data found by us on casual examination 



16 ACTION OF ANTHELMINTICS ON PABASITES. 

of the literature as to autopsy showing that the death of the fluke 
actually follows the administration of the male fern. Salvarsan has 
been commended on the basis of a cessation of sjrmptoms following its 
administration in eight cases of bilharziasis, and opposed on the find- 
ings in five cases in which its administration was without effect. 
Looss questions the benefits of salvarsan as regards the organic 
lesions due to the parasite, while the other writers take exception to 
Joannides's findings as not conforming to other known facts. 

AUTHORS' EXPERIMENTS. 

Being engaged in a study of tapeworm disease of sheep, due to 
Thysanosoma actimoides^ the authors have taken advantage of oppor- 
tunities to test carbon bisulphid and male fern as remedies for this 
disease. At the request of a sheep owner we also tested a certain 
proprietary remedy. This remedy was found on analysis by the 
Biochemic Division of the Bureau of Animal Industry to consist of 
49 per cent ferrous sulphate, 13 per cent arsenious oxid, 8 per cent 
oxids of calcium, potassium, silicon, and magnesium^ and 29 per cent 
organic matter, nature not determined but not containing santonin 
or any other vegetable alkaloid. 

Tests of carbon bisulphid were made by the junior author at the 
ranch of Mr. Wells, near Resolis^ Colo., in July, 1911. A Mexican 
herder at one camp was instructed to cut out six sheep, picking the 
poorest and weakest as being the most likely victims of thysano- 
somiasis. Events proved that some of the sheep selected were really 
too sick for the experiment. 

The experiments were as follows: 

1. Administered 6 grams of carbon bisulphid in capsule to a sheep. Sheep 
crushed one or two capsules and seemed greatly distressed thereby. Repeated 
dose after dO-hour interval. Sheep found dead the next day. Post-mortem 
showed appearances similar to those of hemorrhagic septicemia. A number of 
live bile-stained Thysanosotna found in the enlarged bile ducttt and a number 
of others in the duodenum. One specimen of Thysanosoma was found with th& 
head in the fourth stomach and the rest of the worm in the third stomach; 
this might have been due to post-mortem wandering or to a reverse peristalsis. 
Two specimens of Cysticcrcua tcnuicollis were found adhering to the liver and. 
one to the duodenum. The fluid content of the cysticercl was stained wlthi 
blood. Death was perhaps hastened by the administration of the carbon 
bisulphid. Two doses of 6 grams each had not killed the tapeworms in this, 
case. 

2. Administered 6 grams of carbon bisulphid In capsule. Repeated dose 
after 30-hour interval. Sheep found dead the next day. Post-mortem showed 
api)earances similar to those of hemorrhagic septicemia ; death perhaps hastened 
by the administration of the carbon bisulphid. There were no tapeworms any- 
where, and no lesions, such as thickened and enlarged bile and pancreatic ducts^ 
to show that there had been any tapeworms. 

3. Administered 6 grams of carbon bisulphid in capsule. Repeated dose 
after 30-hour interval. Sheep found dead the next day. Post-mortem showed 



AUTHOKS' EXPERIMENTS. 17 

appearances Bimilar to those of hemorrhagic septicemia. Death was perhaps 
hastened by the administration of carbon blsnlphid. No Thysanoaoma or lesions 
nttrlbntable to this worm were found. 

4. Administered 6 grams of carbon blsnlphid in capsule. Fifty hours later 
administered 4.5 grams of carbon blsnlphid and repeated this dose 24 hours 
later. Killed the sheep 20 hours afterwards. No tapeworms were found on 
antoiMsy, but the gall ducts were thickened and enlarged, as was also the 
pancreatic duct, probably the result of former Infestation with Thysimoaoma. 
No worms had been found, howeyer, in the feces of this or any of the other 
sheep. 

5. Administered 6 grams of carbon bisulphid in capsule. Fifty hours later 
administered 3.6 grams of carbon bisulphid and repeated this dose 24 hours 
later. Killed the sheep 20 hours afterwarda No tapeworms were found on 
autopsy. 

6. Administered 6 grams of carbon bisulphid in capsule. Forty-eight hours 
later sheep was down, with a respiration rate of 210. Sheep found dead 24 
hours later. No eyidences of the efficacy of the drug — that is, dead specimens 
of Thyaanoaoma — ^were found. Other notes regarding this autopsy lost. 

A summaiy of the above experimients shows that sheep No. 1 had 
live tapeworms in the liver and intestines, after receiving two doses 
of 6 grams each of carbon bisulphid on two successive days; that 
Nos. 2 an4 3 after the same treatment had no tapeworms or lesions 
indicating their presence ; and that Nos. 4, 5, and 6 showed no dead 
tapeworms on autopsy. As stated before, no tapeworms were found 
in the feces of any of these sheep. These experiments were incon- 
clusive, but they point to the inefficacy of carbon bisulphid in that 
where tapeworms were found, as they were in one case, after 12 
grams of carbon bisulphid had been administered, the tapeworms 
were alive. 

It should be noted in this connection, as a matter of passing inter- 
est, that no stomach worms were found in these sheep on post-mortenu 

The next set of experiments was made by both of us at Mr. Wells's 
ranch later in July. This time four sheep, selected as probably suffer- 
ing from Thysanoaoma infection, were used to test the ethereal extract 
of male fern, and two sheep in good condition were used to test the 
proprietary medicine previously referred to. The experiments were 
as follows: 

Sheep Nos. 1 and 2 were given two tablets each of the proprietary 
medicine, according to the directions furnished with the medicine. 
No. 1 was killed 24 hours later. A number of Thyaanoaoma were 
found in the gall bladder and intestine, and Hmmonchua contortus 
and Oatertagia hulloaa in the fourth stomach. All the worms were 
alive, although the advertisement of the remedy claimed that the 
dose given would kill any worm in the digestive tract. No. 2 was 
killed 48 hours after receiving the dose. Specimens of Thyaanoaoma 
were found in the gall ducts, two in the pancreatic duct, and a num- 



18 ACTION OF ANTHELMINTICS ON PARASITES. 

ber in the intestine; Haemonchus and Ostertagia in the stomach. 
All the worms were alive. 

The analysis, already given, of this medicine, indicated that it is 
practically inert as a vermifuge and that any improvauent following 
its use would be attributable to the tonics contained in it The nega- 
tive results with this medicine were precisely what might be expected. 
At a time when parasitologists in practical work are not aware of 
adequate remedies for all kinds of worms, and especially of any one 
remedy which is efficacious against all kinds of worms, it is imlikely 
that the manufacturers of proprietary medicines will have this 
information. 

In the male-fern experiment, sheep Nos. 3, 4, 5, and 6 were given 
9 c. c. of the ethereal extract thoroughly mixed with 25 c. c, of 
linseed oil — ^the dose recommended by Railliet, Moussu, and Henry — 
in the morning of four successive days. They were killed the 
afternoon of the fourth day. No. 3 had one dead and partly digested 
Thyaanosoma in the gall bladder; No. 4 had one live Thyaanoaoma 
in the gall duct and one live one in the pancreatic duct ; Nos. 5 and 6 
had no tapeworms. No Hcemonchus was found in any. Live Oster- 
tagia were found in Nos. 1, 2, and 3. All of the sheep had some 
signs of pneumonia, a marked retention of urine, with a slight cys- 
titis, due apparently to the male fern. Considerable purging 
occurred during the last two days, which is attributable to the linseed 
oil. No tapeworms were found in the feces. 

The finding of a dead Thysanosoma in the gall bladder of No. 1 
is a fact pointing to a possible efficacy of the male fern ; the presence 
of live Thys(mo8oma in No. 2 rather offsets this. 

As the experiments were not conclusive, we repeated them later on 
the ranch of Mr. Kennedy, near Amo, Colo. Five sheep were selected, 
one of them being used as a check. Four sheep were each dosed with 
6 c. c. of ethereal extract of male fern thoroughly mixed with 25 c. c 
of linseed oil, on four successive days. The sheep were killed on the 
fifth day. Autopsy findings were as follows: 

1. Twelve Thysanosoma in gall ducts and duodenum and 2 StrongyMdeB 
papillosua in intestine No Haemonchus. 

2. Twelve Thysanosoma in duodenum, 1 in common bile duct, 4 in biliary 
ducts, 1 in gall bladder, and 1 in {lancreatic duct, a total of 19; 4 Hwmonchui 
and 2 Ostertagia in fourth stomach. 

3. Five Thyaanoaoma in duodenum, 1 in gall bladder, and 3 in bile duct8» a 
total of 9; 158 Hwmonchua in fourth stomach and 10 Nematodirtis filicollia in 
intestine. 

4. Seven Thysanoaoma in duodenum and 5 in gall ducts, a total of 12; a few 
Hmmonchus and about 20 Oatertaffia in fourth stomach. 

Ck Check animal. Two Thysanoaoma in the gaU ducts; a few Hcenumchus 
and Oatertagia in fourth stomach and 3 Strongyloidea in inteatine. 
The Thyaanoaoma were ail alive, as were the nematodes. 



OENEfiAL SUMMABT AND CRITICISM. 19 

It appears from these experiments that male fern as administered 
is not efficacious against thysanosomiasis. While the negative find^ 
ings of the former experience are inconclusive, the findings in this 
case are fairly canclusive. The failure of the medicine to exert any 
effect on four infected sheep indicates that male fern is not a remedy 
which could be recommended in thysanosomiasis. 

GENERAL SUMMARY AND CRITICISM. 

It appears from the foregoing that anthelmintics have been 
claimed to be efficacious in 8 cases of human somatic t{eniasis (male 
fern) ; inefficacious in 8 cases of somatic tseniasis in the lower ani- 
mals (male fern) ; inefficacious in at least 6 cases of intestinal and 
extraintestinal thysanosomiasis (carbon bisulphid and male fern) ; 
efficacious in over 14 cases of hepatic distomatiasis (carbon bisul^ 
phid and male fern) ; efficacious in 8 cases of venal distomatiasis 
(salvarsan) ; inefficacious in 5 cases of venal distomatiasis (salvar« 
san) ; and efficacious or inefficacious, according to various authors, in 
an indefinite number of cases of venal distomatiasis (male fern). 

While the figures in the above paragraph are preponderantly in 
favor of the efficacy of anthelmintics against somatic helminthiasis, 
it should be borne in mind that there is much more likelihood of cases 
being published where the administration of a medicine is followed 
by apparent cure of disease than where it is followed by evident 
failure to cure. Further objections to the figures as they stand are 
based on a critical examination of the cases. This criticism may be 
summarized as follows: 

Ziirn's experiments are entirely indefinite and lacking in detailed 
statement. In Feletti's cases one patient died in spite of treatment 
and there was no autopsy, and in the other cases the possibility of 
spontaneous degeneration of the cysticerci, a not uncommon thing, 
is not excluded. De Renzi's cases, as we have already stated, have 
been criticized by Hall (1909) as open to suspicion of error as 
regards diagnosis and the connection between the disease, the treat- 
ment, and the cure. Dianoux's case is open to much the same criti- 
cism as those of De Eenzi. Granting that the diagnosis was correct 
(as it apparently was in this case), the possibility of spontaneous 
degeneration of the parasites is not excluded, and it is not safe to 
conclude that their disappearance was due to the treatment. At least 
one of Hall's cases was not at all conclusive. None of the cases deal- 
ing with distomatiasis specifically eliminate* the possibility of the 
natural death and spontaneous evacuation of the flukes, the usual 
ending of the yearly life cycle^ although the use of check animals, 
where such checks were used, probably meets this objection. Per- 
Toncito's cases show that on the basis of fecal examination the flukes 
apparently were not killed in two cases out of three. Floris and 



20 ACTION OF ANTHELMINTICS ON PARASITES. 

Borini cite no post-mortem findings or final negative fecal examina- 
tions in support of their statements. Among the cases reported by 
Railliet, Moussu, and Henry, autopsy showed that Fasciola hepatica 
in four cases and DicrocoBliimi lanceatum, in all cases had survived 
the full dose advocated by them. None of Joannidte's cases were 
followed by post-mortem examination; and, so far as case records 
are available, no cases of bilharziasis treated by male fern have been 
followed by post-mortem examination to ascertain whether the ad- 
ministration of the male fern had resulted in the death of the flukes. 
In spite of these objections, the total evidence collected here indi- 
cates that further work along this line is necessary and desirable. 
It is possible that the common opinion that medicines administered 
per orem or subcutaneously can not be successfully used against 
metazoan parasites outside of the digestive tract, that the higher 
orders of parasites can not be killed by a selective action of drugs 
without injury to the host animal in whose tissues they are located, 
may be erroneous. Improved technic and better medicines have 
marked great advance in the treatment of protozoan and bacterial 
diseases. Similar improvements have led to greater success in the 
treatment of intestinal helminthiasis.. May not careful experiment 
lead to the same results in the treatment of somatic and extra- 
intestinal helminthiasis 1 The subject is worth investigating. The 
location of metazoan parasites often makes surgical treatment im- 
possible, dangerous, or improfitable. Adequate methods of medici- 
nal treatment would have great medical and economic value as well 
as scientific interest. The present state of our knowledge does not 
warrant any conclusion other than this, that a great amount of addi- 
tional work is necessary and desirable. 

BIBLIOGRAPHY.* 

Alessandrini, Giulio. 

1908. — Contributo alio studio delle malattle parassltarle deUe pecore <BolL 
Soc. zool. Ital., Roma, v. 17, 2. 8., v. 9 (11-12), pp. 392-400, 1 table. [WM 

f 

BOBINI, Agostino. 

1911. — La dlstomatoBl e sua cura <Gazz. d. osp., Mllano, v. 32 (143), 28 
nor., pp. 1515-1516. [W".] 

OONOB, A. 

1911.— Bllbarziose et 606 <BuU. Soc. de path, ezot. Par., v. 4 (1), 11 Jan., 
pp. 45-47. [WM 

-Curtice, Coopeb. 

1889a. — Tapeworm disease of sheep of the western plains <4th & 5th Ann. 

Rep. Bureau Animal Indust, U. S. Dept. Agrlc, Wash. (1887-88), pp. 

167-186, pis. 1-2, figs. 1-15. [W.] 
1890c. — The animal parasites of sheep. 222 pp., 36 pis. 8*. (U. S. Dept. 

Agrlc.) Washington. [WM 



^ This bibliography Is prepared in the style used in Bulletin 89 of this bureau, Index- 
•Catalogue of Medical and Veterinary Zoology. 



BIBU06RAPHY. 21 

DAT, H. B. ; & RiCHABDS, Owen. 

1912. — ^The treatment of bUhaniasls by salvarsan < Lancet, Lond. (4626), 
V. 182, V. 1 (17), Apr. 27, pp. 1126-1127. [W, W».] 

D£v£, F. 

1911. — Greffe hydatlqne et fous^^re male <Gompt rend. Soc. de bioL, Par., 
V. 71 (SI), 17 nov., pp. 420-421. [WM 

DiANocx. [Dr.] 

1909. — Cystlcerqaes et foug^re mftle <Qaz. mM. de Nantes, t. 27 (49), 
4 d^., pp. 1026-1029. [W".l 

Feletti, Raimondo. 

1894c. — ^La cure de la cystlcercose avec la fougdre m&le <Mercredl m6d.. 
Par. [V. 5] (35), 29 aoflt, pp. 417-4ia [W".] 

Flobis, Rudolph. 

1907. — ^A 8z6nk6neg alkalmaz&sa a m^telykCr ellen <iJlat lapok, Budapest, 

V. 30 (45), nov. 9, p. 544. [W*.] 
1908. — Schwefelkohlenstoff gegen distomatosls. [Abstract of 1907] <Berl. 

thlerarztl. Wchnschr. (29), 16. Jull, p. 618. [WM 
1908. — Carboneum sulphuratum In the treatment of distomatosls. [Abstract 

of 1907 <Am. Vet. Rev., N. Y., v. 34 (2), Nov., pp. 242-243. [W\l 

FOllebobn, F. ; & Webner [Dr.]. 

1912. — ^Ueber Salvarsanwlrkung bel Bllharzlose nebst Bemerkungen Uber 
das Ausscliltlpfen der Mlracldlen <Deutsche med. Wchnschr., Lelpz., v. 
88 (8), 22. Feb., pp. 351-^2, figs. 1-2. [W'.] 

Gbassi, Giovanni Battista; & Galandbxtccio, Salvatobe. 

(1884b). — Intomo ad una malattla parassltarla (cachessla Ittero-verminosa 
o cachessla acquosa o marclaja) <Agrlc. calabro slculo, Glrgentl, v. 9 (11). 
1886a. — Idem <Atti Accad. Gloenla dl sc. nat In Catania, 3. s., v. 18, pp. 
229-234. [W.] 

Gbenside, F. G. [V. S.] 

1884a. — ^Tapeworm In lambs <9. Ann. Rep. Ontario Agrlc. Coll. & Exper. 
Farm, Toronto (1883), pp. 200-203. [MS. dated June 25, 1883.] [WM 

Haix, Maubicx C. 

1909. — ^A discussion of De Renzrs treatment of somatic taenlasls with male 
fern, and some tests- of the treatment In gld. <Am. Vet Rev., N. Y., v. 86 
(3), Dec., pp. 328-337. [W'.] 

JOANNIDftS, "NlOOLAB Z. [Dr.] 

1911. — ^Die Wirkung des Salvarsans auf die Bilbarzia <Deat8die med. 
Wchnschr., Leipi., v. 37 (34), 24. Aug., p. 1551. [W*.] 

Looss, A. [Ph. D.] 

1912. — Ueber die sogenannte Hellung der BilharzloslB dnrch Salvarsan 
<Deutsche med. Wchnschr., v. 38 (2), 11. Jan., p. 70. [W'.l 

Millee, Fbank H. [D. V. S., Vet., Westminster Kennel Club, New -York.] 

1904a. — ^H^emorrhaglc colitis of the dog due to infection with the Tricho- 
oephalus depreasiusculus. (True whip worm) <Am. Vet Rev., N. Y., 
V. 28 (8), Nov., pp. 722-729, 1 pi., 3 figs. [W, W",] 

Motrssu, G. 

1910. — ^Traitement des maladies a cysticerques par Teztrait 6th6r6 de 
fougdre male <Compt rend. Soc. de blol.. Par., v. 68 (14), 29 avrll, 
pp. 72(^722 [W, W".] 

PtelOAUD, HeNBI. 

1906. — ^Du traltement de la distomatose <Progrds v6t., Agen, an. 21, n. s., 
V. 28 (28), 10 d^.. pp. 87a-880. [WM 



22 ACTION OF ANTHELMINTICS ON PARASITES. 

Pebbonctto, Edoabdo. 

1885c. — Straordinario nnmero di dlstomi nel fegato dl ana pecora affetta 
da cachesala ittero-verminosa e Taxlone mortale sopra di essl d^ll'estratto 
etereo di felce maschio < Medico vet, Torino, y. 32 (1), gennalo, pp. 
14-16. [W» ] 
1886f. — Sulla cachessia itten>vermino0a. Stndi e consideraslonl < Ann. r. 
Accad. d'agric. di Torino (1885), v. 28, pp. 83-96, 1 pi., figs. 1-3. [W.] 

PfiBBOIf CITO, Edoabdo ; & Bosso, Q. 

1894a. — ^Experiences sur la resistance ritale des lances d*<Bstre iOastro- 
philus equi). [Read before Ck>ng. internat d'hyg. et de d^mog. de 
Budapest, 8 sept] <Rec. de m^d. v^t, Par., v. 71, 8. s., v. 1 (21), 15 nov., 
pp. 657-666. [W, W"*.] 

Powers, Rat M. [D. V. S.] 

1909. — ^Stomach worm disease of sheep and young cattle <Bull. 142, South 
Carolina Agric. Exper. Station, Clenison Agric. Ck)U., Columbia, S. C. 
Mar., pp. 1-19. [WM 

Raiixibt, a. ; Moussu, G. ; & Henby, A. 

1911a. — Essals de traitement de la distomatose <Compt rend. Soc. de biol.. 

Par., V. 70 (11) 24 mars pp. 427-429. [WM 
1911b. — ^Essals sur la propbylaxie et le traitement de la distomatose <Rec. 

de med. vet. Par., v. 88 (7), 15 avril. pp. 232-238. [W*.] 
1911c. — Recherches sur le traitement de la distomatose du mouton <Ck)mpt. 

rend. Acad. d. sc., Par., v. 152 (17), 24 avril, pp. 1125-1127. [WM 
1911d.— Idem <Rec. de med. vet, Par., v. 88 (9), 15 mai, pp. 283-289. 

[WM 

De Renzi. [Dr.] 

1908. — Behandlung des Cysticercvs und Echinococcu8 mlt Extract fllicis 

mar. aether <Berl. klin, Wchnschr., v. 45 (50), 14. Dec., pp. 2216-2217. 

[WM 
1909. — L'extrait ethere de fougere mftle dans le traitement de la cysticer- 

cose cerebrale et de rechinococcose hepatlque. [Abstract of 1908, by 

RalUiet] <Rec. de med. vet, Par., v. 86 (5), 15 mars, p. 185. [W, W°.l 

ROMAGNOLI, M. [Dr.] 

(1903a).— [?] <Mod. zooiatro, Torino (4), 25 feb. 

1903b. — Contre la distomatose du mouton. [Abstract of 1903a, by Ma this] 

<J. de med. vet et zootech., Lyon, v. 54, 5. s., v. 7, 31 mal, p. 301. [W, 

W".] 
IWSc. — Salol in hepatic distomatoses. [Abstract of 1903a, by A. Liautard] 

<Am. Vet Rev., N. Y., v. 27 (8), June, p. 245. [W% W", VT.] 

Sand WITH, F. M. [M. D., F. R. C. P., Prof. Med., Cairo.] 

1009b.— BilharzlflSls <8yst Med. (Allbutt & Rolleston), N. T. & Lond., 
V. 2, pt. 2, pp. 864-888, flgs. 162-167. [W*, W".] 

Stiles, CntABLKS] Wardell. 

1902qq. — Further investigations on verminous diseases of cattle, sheep, and 

goats in Texas < 18. Ann. Rep. Bureau Animal Indust., U. S. Dept. Agric, 

Wash. (1901), pp. 223-229. [W, W% Lib. Stiles.] 
19041. — Illustrated key to the trematode parasites of man <Bull. 17, Hyg. 

Lab., U. S. Pub. Health & Mar.-Hosp. Serv., Wash., Aug., pp. 1-66, flgs. 

^S8, pla 1-3, figs. 1-8. [MS. dated Aug., 1903] [W, W", W'.] 

Stiles, Ch[arles] Wardell; & Pfender, Charles Alexander. 

1902a. — ^The failure of thymol to expel whipworms {Tnchuris depreesiui- 
aula) from dogs <J. Comp. M. & Vet Arch., N. Y., v. 23 (12), Dec., 
pp. 733-740. [W, W".] [Also reprint: W', W", Lib. Stilea] 



BIBLIOGRAPHy. 



23 



Taab» Gtula. 

1907a. — X sz^nk^neg hatAsa ^s alkalmazAsa a gyomorban, valamint a belek- 
ben 613Bk5d(5 b^gOlyftlcz&k ^s ors6f^rgek ellen <Allat lapok, Budapest, 
V. 80 (6), feb. 9, pp. 66-66. [W. W".] 

1907b. — Schwefelkohlenstoff gegeii Bremsenlarven iind Spulwttmier. [Ab- 
stract of 1907a] <BerI. tlerUrztl. Wchnschr. (20), 16. Mai, p. 406. 
[W\ W".] 

Wessel, W. 

1901a. — ^Abtreibnng von Gastraslarren bel Fohlen durch Schwefelkohlen- 
stoff <Berl. tierHnBtl. Wchnschr. (9), 28. Feb., p. 156. [W, W".] 

ZthiN, Fbiedbich Anton. 

1882a. — Die Schmarotzer auf und in dem Korper unserer Haussftugetiere, 
sowle die dnrch erstere veranlassten Krankheiteu, deren Behandlung and 
VerhOtung. 1. Theil : Tierische Parasiten. 2. Aufl., zTi+316 pp., 4 pis. 
8'. Weimar. IW', W".] 



ADDITIONAL COPIES ofthiipabllottiim 
'^ may be prooored from the Supsbimtend- 
BNT or DocuMBinB, Govermnent PrlntiDg 
OiBoe, Waahington,D. C. ,at 6 cents per oqpy 







lamed September 17, \K.% 

U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF ANIMAL INDUSTRY.— BULLEXi^|[fg. j_j_ 

A. D. MELVIN, CwBf op Buibu^ ■ ^M 

00116 1912 

''*'!'. OF r«vo*' • 

METHODS OF CLASSIFYING THE 
LACTIC-ACID BACTERIA. 



LORE A. ROGERS, 
Bactetiologist, Dairy DivisitM, 

AND 

BROOKE J. DAVIS, 
j4ssistanl. Dairy Division. 



BUREAU OF ANIMAL INDUSTRY. 



Chief: A. D. Melvin. 

Astistant Chief: A. M. Farrington. 

Chief Clerk: Charles C. Carroll. 

Animal Husbandry Division: George M. Rommel, chief. 

Biochemic Division: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsay, chief. 

Meat Inspection Division: Rice P. Steddom, chief. 

Pathological Division: John R. Mohler, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: £. C. Schroeder« superintendent. 

Editor: James M. Pickens. 

DAIRY DIVISION. 

B. H. Rawl, Chief 

Helmer Rabild, in charge of Dairy Farming Investigations. 

S. C. Thompson, in charge of Dairy Manufacturing Investigations, 

L. A. Rogers, in charge of Research Laboratories. 

Ernest Kelly, in charge of Market Milk Investigations. ^ 

Robert McAdam, in charge of Renovated Butter Inspection. 

2 






LETTER OF TRANSMITTAL. 



U. S. Department op Agriculture, 

Bureau op Animal Industry, 

WasUngton, D. (7., March 22, 1912. 

Sir: I have the honor to transmit for publication as a bulletin of 

this bureau the accompanying manuscript entitled ' 'Methods of 

Classifjring the Lactic-Acid Bacteria," by Messrs. Lore A. Rogers and 

Brooke J. Davis, of the Dairy Division of this bureau. 

There has hitherto been felt a need by dairy bacteriologists and 

others of a classification of the lactic-acid bacteria into naturally 

related groups by means of characters that can be determined with 

reasonable accuracy and in a maimer ordinarily available. This 

paper describes the study of about 150 cultures isolated from milk, 

butter, and cheese, derived from various parts of the country, with 

the object of laying the basis for a satisfactory classification. 

Respectfully, 

A. D. Melvin, 

Ohief of Bureau. 

Hon. James Wilson, 

Secretary of Agriculture, 

3 



\ 



CONTENTS. 



• Pago. 

Introduction 7 

Thesignificant characters of the lactic-acid bacteria 10 

Morphology ^ 13 

Growth on solid media 14 

Growth in milk 15 

Growth in broth 17 

Reduction of nitrates 17 

Reduction of neutral red , 18 

Liquefaction of gelatin^. 18 

Fermentation of carbohydrates 19 

Conclusions 28 

References to literature 29 



ILLUSTRATIONS. 



Pace. 
Flo. 1. Rate of acid formation in milk at 30^ 0. by cultures freshly isolated 

from milk 14 

2. Rate of acid formiation in milk at 30^ C. after 26 generations (2 years) 

onlactose-agar 16 

3. Frequency curve for gelatin liquefactjon 19 

4. Frequency curves for acid formation by the liquefying cultures 25 

5. Frequency curves for acid formation by the nonliquefying cultures. . . 26 

6. Grouping of cultures and distribution of characters in groups 27 

6 



METHODS OF CLASSIFYING THE LACTIC-ACID BAaERIA. 



INTRODUCTION. 

The grouping of bacteria according to their action on any one 
specific substance usually brings together bacteria related in that one 
characteristic only but entirely unrelated in other respects. It is, 
however, sometimes convenient from a technical standpoint to group 
bacteria in this way. The bacteria concerned in the souring of milk 
have been so grouped for so long that many people have come to 
consider them as a division by themselves and their relation to other 
bacteria has been little considered. The bacteria taking part in the 
souring of milk may be readily divided into four general groups. 

Group I includes those bacteria which sour milk without peptoniza- 
tion or gas formation; they grow poorly on artificial media and fail to 
liquefy gelatin. Morphologically they show same variation, usually 
appearing as a coccus or very short bacillus in pairs or in chains of 
varying lengths. The bacteria of this group are the ones ordinarily 
designated as the lactio-acid bacteria and have been described under 
various names. They have a very general distribution and their 
presence in milk is so constant that they may be considered as 
normal inhabitants of this medium. 

Group II includes the bacteria forming an acid curd with evolution 
of gas. This embraces varieties of BacHJlus coli and Bacterium aerogenes 
or the BaciUus dddi laetici of Heuppe. The members of this group 
are readily distinguished from those of Group I by their abundant 
growth on artificial media, the vigorous evolution 6f gas, and the 
marked di^erence in their morphology. An examination of milk 
usually reveals their presence in small numbers, but their number is 
increased by the influence of high temperatures or insanitary con- 
ditions under which the milk has been collected or held. 

Group III includes those bacteria forming an acid curd which is 
subsequently partially peptonized. The bacteria of this group have 
been little studied in their relation to milk. It will be shown that 
this description applies to varieties only distantly related to our 
Group I as weU as to some closely connected with this type. 

Group IV includes the high-acid-forming bacteria of which the 
Bacillus bulgaricus is the type. This oi^anism is distinguishable from 

7 



8 CLASSIFYING LACTIC-ACID BACTERIA. 

those of the preceding groups by its slender rodlike form, its charac- 
teristic colonies on agar^ its inability to grow in ordinaiy artificial media^ 
and its growth in the presence of free acid. BdciUus hulgaricus has 
been studied in its relation to the fermented milks extensively used in 
Turkey and the neighboring countries. It has recently been 
shown * *, ', *, that it is very widely distributed and may be isolated 
from almost any sample of mixed nulk. Its growth at normal 
temperatures is so slow that it is improbable that it is a factor in the 
ordinary souring of milk. 

It is obvious that these groups are connected only by their ability 
to ferment lactose to acid and the consequent precipitation of the 
casein. Groups I, II, and IV are evidently related to each other in no 
other way. The identity of the bacteria of Group III in so far as they 
occur as milk bacteria has not been established. The need of work 
on methods of classification rather than on descriptions of new 
varieties or rearrangement of old names and descriptions is ex- 
emplified by the confused nomenclature of the bacteria included 
under Group I. We find in the literature such names as Bacterium 
lactia acidi, Bacillus lactis addiy B, addi Jactici, B. ffuntheri, and 
Streptococcus lacticus, all of which, so far as can be determined by 
published descriptions, may be included in Group I. These names 
are based on variations in morphology, differences in growth on 
artificial media, on the rate of acid formation in milk, and various other 
characteristics of doubtful significance and uncertain stability. In 
the light of recent investigations these names and their accompanying 
descriptions have little more than a historic interest. They represent 
the attempt to establish types by the study of an isolated individual 
organism with little regard to its relation to other similar individual 
organisms. 

Approached &om the standpoint of the dairy bacteriologists, the 
lactic-acid bacteria have been considered as a sharply defined group 
peculiar to milk. The students of pathogenic bacteria have been 
inclined to iQok on them as a variety of some of the pus-forming 
streptococci. 

The opinion that the term lactic-acid bacteria covers a group of 
species or varieties and that the names and descriptions already pub- 
lished do not r^resent the true grouping is reflected in the frequent 
attempts to establish means of separating the group into stable 
species or varieties. McDonnell^ attempted to do this, basing his 
descriptions largely on the effect on milk. A somewhat similar course 
was followed by Weigmann." Mtlller^ found a correlation in the 
solution of red blood corpuscles and the agglutination of immune sera 
by the streptococci of sour milk and certain pathogenic streptococci, 

• The refeienoe flgures relttte to the list of reliBrenoeB to llteratare at the end of this bulletin. 



INTRODUCTION. 9 

and considered that this indicated a relationship. Lohnis^ has made 
a classification of the lactic-acid bacteria based largely on gas f orma- 
tion^ coagulation of milk, formation of slime, and liquefaction of 
gelatin. Conn, Esten, and Stocking* have used in their descriptions 
the action on milk and the usual culture characteristics. Heinemann* 
as a result of his studies on the bacteria of sour milk, excludes the 
name of Bacillus dddi lacticiy and concludes that aside from the part 
taken by B. aerogenes and possibly by B, coli the spontaneous souring 
of milk is brought a'bout by the Streptococcus Jncticus of *Kruse, an 
organism identical with the common streptococci of sewage and 
pathological conditions. He bases this conclusion on the similarity 
in morphological, cultural, and pathogenic properties. 

All of this work and much more of a similar nature adds little to the^ 
systematic^arrangement of the lactic-acid bacteria. It is generally ad-f 
mitted that it is difficult to identify cultures of any but the best known\ 
and most carefully studied bacteria by the published descriptions. 
Cultures which seem identical when written descriptions are compared 
are found to be distinct when they are grown side by side under 
uniform conditions. This error in identification is due partly to the 
difficulty of conveying the appearance of an object by words, but in a 
larger degree to the instability and unessential nature of some of the 
characters employed in separating one bacterial species or variety 
from another. The inadequacy of the ordinary methods is partic- { 
ularly felt when one attempts a description of the lactic-acid bac- 
teria. The cells are small and the morphologicaT differences are 
uncertain and inconstant. The growth on solid media is scanty and 
devoid of distinguishing characteristics. While many of the physio- 
logical tests which are found of great value in some groups fail when 
applied to the lactic-acid bacteria, others, notably the acid fermenta- 
tions of sugars, offer a possible means of differentiation for members 
of this group. 

Variations in the ability to ferment sugars have been observed, but 
the use of these variations in classifying or identifying cultures has ! 
been limited for two reasons. There has been a belief that the < 
fermentative power was not constant; that this property could be 
lost or acquired so readily that it could not be used to differentiate 
one culture from another with any certainty. The more conmion 
objection, however, is that the separation on the basis of sugar fer- | 
mentation divides the lactic-acid bacteria and others possessing the , 
same general characteristics, not into natural groups, but into 
innumerable varieties. 

The use of tests of this kind in the usual way by which the f ermen- 
ti|tion of, or failure to ferment, a certain substance sets the culture 
so reacting apart from all other cultures gives an endless dichotomy 
61104^-12 2 



10 CLASSIFYING LACTIC- ACID BACTERIA. 

limited only by the number of test substances. Consequently, the 
ordinary use of sugars has increased rather than diminished the con- 
fusion now existing in the classification of the zymogenic ^bacteria. 
It is obvious that what is required, in systematic bacteriology is not 
descriptions of new species or a rearrangement of names, but the 
establishment of means of classification applicable technically and 
correct biologically. No one basis of classification can be used for all 
groups of bacteria, but certain fundamental principles should govern 
any method of arrangement. Two of the most obvious principles on 
which the selection of characters for classification should be based 
may be stated as follows: The characters should be constant; they 
should be so selected that they show real biological relationships. In 
other wordS; bacteria should be arranged by means of characters that 
can be determined with reasonable accuracy and by means ordi- 
narily available into groups whose members are related naturally 
rather than by artificial bonds, and these characters should be so 
constant and so distinctive that identical organisms can always be 
placed in the same group. 

This paper records an attempt to determine which of the charac- 
ters exhibited by the lactic-acid bacteria fulfill these conditions. No 
attempt has been made to classify or name any members of this group 
or to fix its place in the general bacteriological system. 

THE SIGNIFICANT CHARACTBBS OF THE Z«ACTIC-ACID BACTBRIA. 

The morphology, staining reactions, cell grouping, cultural charac- 
ters, and growth in milk were considered, but more attention was given 
to the fermentation tests. We studied about 150 cultures isolated 
from milk, butter, and cheese obtained from various parts of the 
country. This collection included, in addition to the typical milk- 
curdling, nonliquefying, lactic-acid bacteria, a number of cultures 
curdling milk with subsequent digestion and which formed on gelatin 
plates small saucer-shaped liquefactions surrounding a solid colony. 

We have determined on these cultures the morphology, Gram's 
stain, cell grouping, in many cases formation of capsule, the nature 
and amount of growth on lactose-agar slopes and in gelatin stabs, 
the rate of liquefaction of gelatin, the nature of growth in broth^ 
growth in milk, the reduction of nitrates and of neutral red, and the 
formation of acid in broth containing various test substances. In 
these fermentation tests we have usea the sugars lactose, dextrose, 
galactose, saccharose, and rafiinose, the alcohols mannite and glyc- 
erin, and the polysaccharid inulin. The results of these determina- 
tions are given in Table 1. 



SIGNIFICANT CHARACTERISTICS. 11 

Table I.— Significant characterixtict of acid-forming bacteria derived from miii, buUer, 



«, 1.... 




~ 


+ 


+ 




— 

+ 


_ 


7 


Hex 








+ 






+ 


























efa.'.::::: 














+ 






«b 










+ 




+ 






« 








































flft.'.i:::: 




















7li 










+ 










Je 








































tlv.:.'.'.'. 








'+' 












» : 








+ 


+ 


























a-:::::: 


::]:::: + 














..I....I + 


";"i + 












7n 




.... + 


+ 


























Tp'.:::::; 


-X'...\ + 














7q 




*::. + 


+ 




+ 






7» 






+ 










1 


::;:::! + 


















...i + 


"\\\ + 






+ 












....1 + 


+ 




'+ 






X.'..'.'.V. 






+ 


....t + 


+ 


.... 








7r 






+ 


....] + 












I 














+ 














::::,■+■ 


> 










■b"!!!! 




















Bd 




z. 




'.'.'.'.{+' 


+ 


















.... + 












«f.".::::: 




'.'.'. 




....] + 












3;::;:: 




... + 








+ 










+ 


....' + 


+ 










•i 








....; + 






+ 






1:::::: 




'+' 


+ 


'.'.'.'.\'+' 


'+" 




+ 


+ 








+ 










+ 






Sj:::;: 






+ 


::::i; 








- 








+' 


::::!-+- 






'+' 














....i + 


'+' 




+ 






»r 






+ 1 + 


+ 




+ 






ti. 




:::: + 


....1 + 


+ 




+ 






Tbe 






+ 








+ 






»•■:::: 






+ 




^ 


I 


+ 






bj 










+ 






















+ 




+ 






bp::::: 
















+ 






bq 
















+ 






Tbc. 
















+ 


















+ 




+ 






Tbt 
















+ 




Tbv. 
















+ 




Tbi 




















tj 












'+ 


z 


'+' 


- 


a"'.'.'.'. 
















+ 




1* 








































td'.'.'.::: 


















- 


» 












- 


- 


+ 




fe;; 












~ 


t 


+ 


- 


m 


















- 


■a-.v;,-; 










~ 


z 


^ 





d 
















- 






















01 



380 


t.31S 


awo 


9.000 


9.009 


.198 


9.000 





Sll 


.3<0 


.HO 


.000 


.000 


.334 


.009 




3tl 


.*W 


.122 








.000 






.433 










.000 










.000 






.000 




as8 


:jis 


:405 


.300 


'.m 




.171 




3U 




.000 


.000 




.288 






wa 






.ox 






iooo 












!oao 




.000 






:43i 


looo 


:ooo 


.000 


:34i 


.000 




378 


.414 


.450 


.027 




.283 


.000 




W3 




.406 








.000 




305 


■JIJ 


:!8S 


'ois 


:ooo 


.3*3 


.000 

.000 




274 


:3«7 


.405 


!ooo 




.054 


.000 
















.000 




«a 












.000 






:3g7 


^000 


iooo 


:ooo 


:423 






378 


.878 


.000 


.000 


.018 


.307 


:ooo 










.000 






.000 










.000 






.000 










.000 




!396 


.008 




388 


'.3U 


:w4 


.000 


:i25 


.243 


.000 




30e 




.009 








.000 




M4 












.000 






'.3e» 




!ooa 


iooo 








388 


.171 


:ooo 


.000 


.380 


:10s 


:ooo 










.283 


.283 


.225 


.000 






















'.Kl 


:ooo 




:ooo 


1216 


iooo 




3«e 


.uo 


.000 






.306 












^009 
















.000 










43a 


:378 


ilol 


.000 


'.■KH 


!ooo 


:oo9 




608 










.414 


.000 












'.3U 




.000 










'.^t 




'.V7 








;4M 


'.va 


.072 


:oi8 


.334 


iooo 




S30 






.030 




.234 


.000 










.000 












;279 


.■3J8' 




.jii' 


.'iw 


'.003 




7W' 


.380 








.234 


.000 






.423 






!oo9 














!ooD 




!343 






asa 






.342 


:ooo 


.171 






180 


.279 


.387 


.oaa 


.0*5 




.000 




386 








.000 








390 








.083 


!3»e 










:ooo 


:oo9 


.000 


.388 


:oi8 




2H 


.207 




.000 


.083 








3M 










!234 














.'666" 












iooo 


imo 




:39« 


:oi8 




306 


il 


.000 


.000 


:ooo 


.380 
.333 


.000 




M« 




009 


!<»a 


'009 


!441 


009 




2OT 


1387 


ins 


.038 


:ooo 




iooo 




«1 


.156 




.000 


.036 














.000 














!28S 


.009 




!351 


!oas 




SS8 




.009 


.000 


;oi8 


.414 


.000 




iil 


.144 


.225 












225 






!ooii 




'.3-H 






4U 




lass 






.333 






eoe 


:248 


.000 




:01s 


.414 


:o4s 




431 


.260 


.324 




.3-8 








Ml 




















!d99 


.038 


!oo9 










!ms 






.018 


;3i5 


:ooo 




513 


.261 


!otl3 


'.am 




.306 







CLASSIFYING LACTIC-ACID BACTEEIA. 



lObc.. 
IDbG.. 



ffiv.: 

13ai.... 
I3«..- 



:!S 



MOBPHOLOQY. 13 

Table 1. — Signifieanl charaderwlici qf aeid-forming bacteria derived from milk, hutUr, 
and dieeie — Continued . 

er cent larttc Kid in broth atler 7 da]^ at 30* C 



a-: 



|,[p,« 



[).ozT 1.027 tt-tat 0. 



MORPHOLOQT, 

The cultures examined showed four more or lees distinct tjrpes. 
The liquefying group included a number of cultures of micrococci, 
with frequent grouping in tetrads. This was associated with good 
growth on agar and certain fermentative reactions which made them 
easily distinguishable from the liquefying cultures with the morphol- 
ogy of the typical lactic bacteria. The nonliquefiers, excepting a 
few cultures of micrococci, showed three variationa. Cells may be ' 
nearly or quite round. When in this condition they are usually 
found in chains of four or more cells. Single cells or pairs of cells 
are almost always oval and sometimes are distinctly of the bacillus i 
type. A slight variation is sometimes found in that the cells are ! 
somewhat pointed at one end. All of these types can usually be found I 
in the same culture and not infrequently in the same microscopic 
field. 

The question of the classification of the lactic-acid bacteria as cocci 
or as bacilli has been much debated and is yet in an unsettled condi- 
tion. The formation of chains, on which much emphasis is placed 
by some writers, is not pertinent, as the tendency to form chains is 
as common among the bacilli as among the streptococci. In our 
present state of knowledge the proper placing of these bacteria is ^ 
largely a question of opinion or of definition. No satisfactory settle- j 
ment can be reached until we have sufficient knowledge to establish 
the natural relations of the lactic-acid bacteria with other groups. | 
Kven in this case it is probable that close relationship will he traced 
on the one hand with groups that are distinct cocci and on the other 
with groups that are unquestionably bacilli. 

It may be stated in this connection that one of our cultures (7dv), 
not differing morphologically from other cultures of the typical 



14 



CLASSIFYING LACTIC-ACIO BACTERIA. 



lactic type, was actively motile. This culture was pronounced by 
Dr, Heinemann to be a typical Streptococcus Idcticus, except that it 
did not curdle milk promptly. 

All of these cultures stain readily and are Gram positive. A cap- 
sule could usually be demonstrated if the test was repeated under 
varying conditions, indicating that it is formed only under certain 
circumstances. The circumstances under which a capsule was found 
indicated that it was in some way connected with the acidity of the 
culture. 




./L^l££ 



Fio. 1.— Rate of acid formation In milk at 30* C. by cultures freshly isolated from milk. 

GROWTH ON SOLID MEDIA. 

Little need be said under this h^ad, although the growth of the 
lactic-acid bacteria on agar and gelatin has been described in great 
detail. The growth is always scanty, and the variations, which are 
very slight, are due more to differences in the chemical and physical 
condition of the medium than to varietal distinction. 

Some real variation may be observed in the size of mature gelatin 
colonies, but this is so influenced by the medium and the number of 
colonies on the plate that it is of little value. Variations of this kind 
are probably merely expressions of a tolerance or intolerance to 
certain conditions which could be determined with much greater 



GROWTH IN MILK. 



15 



accuracy by other methods. The reaction of a particular lot of 
gelatin may produce large colonies of one culture while it limits the 
growth of another culture to colonies of almost microscopic size. 



QBOWTH IN MILK. 



The time required to curdle milk under definite conditions has been 
employed almost universally in describing lactic-acid bacteria, 
although it is generaUy admitted that this property is variable, 
especially after the culture has been grown under artificial conditions. 
This variation is illustrated by figures 1 and 2. 




,/l (Mrs 



/ 2 3 4^ S 

Fxo. 3.— Rat« of acid formation In milk at 30* C. after 26 generations (2 years) on ftctofl»«gar. 

Figure 1 shows a variation in the freshly isolated cultures from 7b, 
which failed to curdle milk in 5 days, to 7k, which curdled milk 
promptly, forming nearly 1 per cent of acid in 48 hours. Two years' 
growth under uniform conditions reduced these difTerences materially. 
The weaker cultures changed little or not at all, but the more active 
ones lost much of their vigor; that is to say, long-continued growtli 
under uniform conditions tended to reduce these cultures to a common 
level. It is not easy to restore this lost vigor. Repeated transfers 
in milk increased the activity of some of the cultures, but failed to 
bring the more active ones back to the rapid fermentation of the fresh 
cultures. It is probable that these differences are due to a variation 
in the vitality rather than to a variation in the particular function 



I 



16 



CLASSIFYING LACTIC-ACID BACTERIA. 



of forming acid from sugar. In these studio it was frequently 
observed that those cultures curdling milk tardily or not at aU multi- 
plied slowly and never attained the numbers reached by the cultures 
curdling milk in a short time. This is illustrated by Table 2, in which 
is given the acid formation and rate of miiltiplication of two cultures, 
one curdling milk in a short time and one failing to curdle milk in 24 
hours. Flasks of milk were inoculated from fresh milk cultures and 
incubated at 30° C. 

Tablb 2. — Relative rate of multiplication and acid formation in milk. 





Slow acid former. 


Rapid acid former. 


Houis 
tarn 














iDooala- 




Bacteria 




Bacteria 


ti09. 


Acidity. 


per cubic 
oentimeter. 


Acidity. 


per cubic 
oentimeter. 




Percent. 




Percent. 







0.216 


357,000 


0.230 


350,000 


3 


.216 


586.000 


.225 


660,000 


6 


.225 


1,600,000 


.225 


2,000,000 


9 


.226 


16,900,000 


.225 


46,000.000 


12 


.290 


59,500,000 


.261 


157,000,000 


24 


.306 


710,000.000 


.900 


1,830,000,000 



It will be observed that in a general way the acidity in each case 
is proportioned to the number of cells present. This ia in accordance 
with the observation of Rahn/® who calculated the amount of acid 
formed in relation to the number of cells in the culture and found 
that this ratio was constant,, although when only a small number of 
bacteria were present the amount of acid was so small that it could 
not be measured by ordinary methods. Schierbeck/^ who studied 
this form of variation in the lactic-acid bacteria, found that by replat- 
ing and making subcultures new cultures could be obtained, some of 
which followed the active fermentation of the original, while others 
were slow acid formers. In some of these cultures the rate of acid 
formation could not be varied by subsequent plating and selection, 
but cultures in which the ability to ferment lactose rapidly seemed 
to be fixed could be changed to slow fermenters by growii^ ,them in 
milk containing a small amount of carbolic acid. Buchanan and 
Truax " attempted to fix strains of the lactic-acid bacteria by selec- 
tion and transfer from tubes of lactose broth showing wide differ- 
ences in acidity. They failed entirely and concluded that "im- 
pressed variations do not appear to be heritable.'' It seems propa- 
ble that they were unable to fix these variations because they were 
working, not with variations in a function, but with the rate of 
multipUcation, something which may be controlled by an endless 
chain of circumstances. For the same reasons this characteristic 
can not be successfully used as a basis for classification. 



REDUCTION OP NITRATES. 17 

GROWTH IN BROTH. 

The growth in a medium of this nature should be considered as the 
expression of certain pecuUarities not evident on superficial examina- 
tion. A cloudiness or turbidity iS; with the lactic-acid bacteria, an 
evidence of rapid growth, and it is governed more by external condi- 
tions than by the nature of the culture. Cultures which remain clear 
in nonsaccharine broth may be cloudy when certain sugars are added, 
and others may show cloudiness when dibasic potassium phosphate 
is added, but not in its absence. Profuse cloudiness is usually fol- 
lowed by a clearing and the accumulation of a sediment coinciding * 
with the checking of the growth by- increasing acidity. Some few 
cultures, however, never show turbidity, and the broth remains per- 
fectly clear with no evidences of growth, although a high acidity is 
produced. This is perhaps due to the tendency to form tangled 
chains possessing in the aggregate a specific gravity greater than the 
broth. Mtiller ^' states that a clouded bouillon is associated with the 
formation of single cells or pairs, while a clear bouillon is coordinated 
with the formation of long chains. In his work he found that the 
cultures that never clouded the bouillon were .the "Gait Stamme" 
found associated with yellow mammitis. When the failure to cloud 
the broth is fixed and constant it may be of some assistance in clas- 
sification. 

REDUCTION OF NITRATES. 

The reduction of nitrates to nitrites was determined by growth in 
the following medium for 7 days at 30° C. 

Peptone gram. . 1. 

Potanium nitrate gram. . 0. 2 

Water (distilled) c. c. . 1, 000 

Of the 147 cultures tested for the reductioii of nitrates, 17 gave a .• 
positive reaction. All of these were differentiated from the typical; 
lactic-acid bacteria by one or more coordinated characters. Twelvel 
were of the liquefying tetrad group. Three (6fl, 7aa, and 7ak), werej 
gas formers, and 7ak was in addition a bacillus larger than the lactic! 
type and grew readily on solid media. One (7cc) resembled the! 
lactic type in morphology but the cells were larger, and in addition! 
to liquefying gelatin and giving an abundant growth on agar it' made } 
milk slimy. Culture 7dw was a small micrococcus. 

None of the cultures belonging to Group I gave any evidence of 
growth in this medium. It is therefore of no value in making sub- 
divisions of this group, but may be a convenient means for the detec- 
tion of cultures resembling the type in many features but differing 
in certain salient points. 



18 



CLASSIFYING LACTIC-ACID BACTEBIA. 



\ 



EEDUCTION OF NEUTRAL RED. 

In making this test the following medium was used: 

Broth (neutral) c. c. . 1, 000 

Dextrose grams.. 5 

One-half per cent solution Grttbler's neutral red c. c. . 10 

The neutral broth was made as follows: 

Beef extract ». grams. . 4 

Peptone grams. . ]0 

Water c. c. 1,000 

• The tubes were examined after incubating at 30** C. for 7 days in 
an anaerobic jar from which the oxygen was exhausted by absorp- 
tion with pyrogallic acid. Gordon '^ considers this test of diagnostic 
value. It has, however, the disadvantage of not always giving definite 
results, although with nearly all cultures the reduction was either 
nil or very evident. Of the 36 cultures reducing neutral red, a large 
proportion ferment the more resistant test substances, such as sac- 
charose, glycerin, mannite, and rafBnose, and 7, or 19 per cent of the 
whole, liquefy gelatin. None of those liquefying gelatin ferment 
rafBnose, while of the .29 nonliquefying cultures reducing neutral red 
75 per cent ferment rafhnose. There is a correlation between the 
reduction of neutral red, the liquefaction of gelatin, and the fer- 
mentation of saccharose, glycerin, and mannite in one group and 
between neutral red, saccharose, glycerin, mannite, raffinose, and 
inulin in another. These correlations are evident in figure 6. The 
faculty of reducing neutral red seems to be usually coordinated with 
other reactions and is therefore of some value in differentiating 
cultures. 

LIQUEFACTION OF GELATIN. 

The value of this test is too generally recognized to need discus- 
sion. In our work we have used Clark and Gage's method of reducing 
the rate of liquefaction to mathematical terms, ignoring the appear- 
ance of the culture. The gelatin tubes were inoculated by spreading 
a few drops of a fluid culture on the surface of* the medium. The 
line of the surface was marked on narrow strips of paper pasted on 
opposite sides of the tube, and the cultures were incubated at 18® 
to 20** C. At the end of 30 days the amount of liquefaction was 
measured and expressed as millimeters of Uquefaction. The results 
of this test are tabulated in Table 3. 

Table 3. — The liquefaction ofgelctin. 



Liqiiefection milUmetere 

Number of cultures 

Feri^ent of total 






lto5 


6 to 10 


11 to 15 


16 to 20 


21 to 25 


108 


3 


10 


10 


2 


3 


78.3 


2.2 


7.2 


7.2 


1.4 


2.2 



Over 25 

2 

1.4 



FERMENTATION OP CARBOHYDRATES. 



19 



These results are platted in figure 3 to show the frequency of 
occurrence of certain arbitrary types. 

This curve gives some indication of a division on the basis of 
gelatin liquefaction into three types, one failing to liquefy, one 
liquefying 6 to 15 millimeters, and one 20 to 25 millimeters. How- 
ever, the total number of liquefying cultures was so small that it is 
safe to make a division into liquefiers and nonliquefiers only, and to 
depend on other tests for further division of the liquefiers. Even 
the separation of the liquefiers from the nonliquefiers is not entirely 

reUable, as it is well known that this character is vari- 
able and under some conditions may be entirely lost. 

If physiological tests are of value they should show 
by correlation or lack of correlation which cultures 
belong properly with the nonliquefiers and which are 
members of Uquefying varieties in which the ability to 
produce a proteolytic enzym has been lost. 

FERMENTATION OF CARBOHYDRATES. 

Mention has already been made of the objections to 
the use of the fermentation of sugars and similar sub- 
stances. The question of the constancy of these reac- 
tions has been the subject of investigation, and while 
there is some disagreement the opinion of those who 
have studied the question most carefully seems to be 
that they are at least as constant as any of the 
characters ordinarily used in classification. Twort,** 

working with gas- 
forming cultures, 
was able to in- 
• duce acid forma- 
tion from sugars 
which the organ- 
ism originally did 

not ferment by repeated transfers in a medium in which this sugar was 
the only carbohydrate furnished. Each transfer was held 14 days to 
allow the cells to work on the sugar after other sources of food had been 
exhausted. Ritchie " concluded that while cultures of Bacillus coli 
tested at different times gave constant fermentation reactions, the 
streptococci were inconstant. Gordon*' tested the constancy of 11 
cultures by passing them through mice. One culture lost ability to 
reduce neutral red and one gained ability to ferment salicin. All 
others remained unchanged. In all of this work the fermentative 
ability was determined by growing the organism in broth, with the 
addition of the test substance and litmus, and the change of the 




^' 



O As 6-/0 //^/S /6-20 zi-es ^^ 

m.m. of //(jfaefi2cf/on. 

Fia. 3.— Frequency carve for gelatin liquefaction. 






20 CLASSIFYING LACTIC-ACID BACTERIA. 

litmus from blue was taken as a positive reaction. A slight change 
in the reaction of the medium may change litmus from blue to red, 
and this acidity may be formed from some substance other than the 
sugar. The reduction of the litmus is certainly not an indication of 
the fermentation of the test substance. The work of MacConkey ^^ 
indicates that under natural conditions these relEictions are constant 
and of value in differentiation. Among the cidtures examined were 
15 cultures of B. typhosus varying from one freshly isolated to one 
grown 16 years on artificial media. These gave identical fermenta- 
tion reactions when tested with various carbohydrates. 

In another paper the same investigator states that the fermentative 
reactions of B, coli remained unchanged after a long exposure to un- 
favorable conditions. He expresses the opinion that one group is 
not derived from another by the loss of characters. 

Harding,** working with Pseudorrumas campestris, an organism 
pathogenic to certain plants, obtained somewhat similar results. Of 
the four substances used for fermentation tests this organism attacked 
only one, but this and all other physiological tests employed were 
identical for the 44 cultures collected from various parts of the 
country. 

In our own work no systematic investigation was undertaken to 
determine the constancy of the fermentation reactions, but all our 
observations tend to prove that the property of forming acid from 
carbohydrates and similar substances is not easily lost or acquired. 
One cultiu*e showing no evidence of ability to ferment saccharose 
was carried for 100 generations, or a period of about one year, on a 
saccharose-agar. At the end of this period the culture still showed 
no fermentation of saccharose and the lactose fermentation remained 
unchanged. 

In no case did any of our cultures show any change in fermentative 
ability on repeated tests. It not infrequently happens that a culture 
failing entirely to give an acid reaction on the first test showed an 
active fermentation when the test was repeated, but this was evi- 
dently due to a failure of the inoculation rather than to a change in 
the organism. Many of the cultures grew so poorly on artificial 
media that they were propagated with difiiculty and transfers fre- 
quently failed to grow. A large proportion of the cultures were 
subjected to these tests two or three times, some of them at intervals 
of several months. The s^ond test almost always agreed with the 
first not only in the presence or absence of fermentation but also in 
the amount of acid formed. This is illustrated by Table 4, which 
contains results on the fermentation of lactose. These figures were 
picked at random. 



FERMENTATION OP CARBOHYDRATES. 



Table 4. — Showing constancy offermentation of lactose. 



21 



Tert. 






Acidity of broth expressed as per cent of lactic acid. 






FlMt 

Second 


0.113 
.117 


0.171 
.261 


0.216 
.171 


0.387 
.306 


0.288 
.225 


0.000 
.144 


0.180 
.261 


0.306 
.288 


0.153 

.135 


0.108 
.090 


0.252 
.243 



With 8ome of the test substances the reaction was always very 
positive; that is^ the reaction remained unchanged or a considerable 
acidity was developed. This was especially noticeable with sac- 
charose, mannite, and raffinose. With others, particularly with 
glycerin, the acid was developed slowly and in such small quantities 
that it was sometimes difficult to determine if there was a real fermen- 
tation or a slight change in the reaction which was iiidependent of 
the test substance. In doubtful cases a retest usually gave definite 
results. 

It is not to be expected that a character of this kind would be 
absolutely fixed. Indeed, the fact that one culture attacks a certain 
sugar while similar cultures do not is evidence that this function is or 
has been a variable one. There is, however, no evidence to show 
that the tendency toward variation in fermentation is any greater 
than in any other character used as a basis of classification. The 
greater difficulty comes in the interpretation of the results. The 
objection that the number of varieties obtained is limited only by 
the number of test substances used is valid only when an absolute 
separation is made on each individual reaction. The usual botanical 
scheme of dichotomous separation when applied to the classification of 
bacteria on the basis of fermentation tests leads only to confusion 
and the rejection of the system. In the card arranged for the classi- 
fication of bacteria by a committee of the Society of American 
Bacteriologists, dextrose, saccharose, lactose, starch, and glycerin 
are used as test substances, and cultures are separated in the usual 
way on the fermentation of or failure to ferment any one substance. 
By the use of these test substances and similar methods we could 
separate our nonliquefying cultures into five varieties. But if it is 
proper to separate cultures on the basis of the fermentation of dex- 
trose, saccharose, or lactose we can use also raffinose and galactose, 
and if glycerin is allowable mannite can not be excluded, while inqlin 
may be as useful as starch. Adding these test substances and follow- 
ing the same principles of division, we obtain no less than 14 varieties, 
and even these are not stable, because the introduction of a new test 
substance would probably subdivide them still more minutely. 

Gordon *® was the first to make an extensive use of the fermentation 
tests. These tests were also used on an extensive scale by Andrewes 
and Gordon '" and by Houston.'* This work show^ the possibilites 
of arranging a large number of cultures in groups around type sets of 
reactions. Not all of the cultures in each group agreed perfectly 



22 CLASSIFYING LACTIC-ACID BACTEBIA. 

with the type. Some failed in one reaction, while others possessed 
some ch^acter not common to the entire group. MacConkey/' 
using similar methods in a study of gas-forming bacteria from milk, 
was able to separate 112 cultures into 17 groups, and even these 
groups were sometimes separated by minor differences only. 

On the basis of the individual reactions it was possible to separate 
these cultures into 64 varieties. This work was continued and 
placed on more scientific footing by Andrewes and Horder,^ and 
especially by Winslow and Rogers, *^,^ who applied the principles of 
biometry to the study of bacteria. In this way has been supplied a 
method of utilizing the physiological tests in such a way that bacteria 
may be collected in natural groups. In tabulating the characters of 
a large number of cultures, frequency of occurrence ^of those with 
certain common characters indicates the type, while the cultures 
varying from these types occur in smaller numbers and form the 
connecting links between the types. This represents the state of 
affairs in nature, while a description based by the ordinary method 
on the characters of a single culture may or may not agree with the 
type. 

In our fermentation tests we have followed Winslow in determining 
the acidity rather than the mere fact of fermentation or nonfermen- 
tation. This is more exact and sometimes gives additional informa- 
tion of value in separating cultures. The medium was made as 
follows: 

Per oont. 

Beef extract 0. 4 

Peptone • 1.0 

Dibasic potassium phosphate 5 

Test substance 2. 

The use of dibasic potassium phosphate is of advantage in that it 
serves to neutralize the acid and thus permits a more active growth 
and higher acid formation. The acid phosphate formed evidently 
checks the growth when a certain concentration is reached. The 
neutralization of culture media by this means is discussed by Hender- 
son and Webster.'* 

The cultures were incubated 7 days at 30° C, with the exception 
of glycerin, which on accoimt of the slow fermentation was held 14 
days, and were titrated while cold against twentieth-normal sodium 
hydrate with phenolphthalein as an indicator. The result of the 
titration is expressed as per cent of lactic acid. Gas formation was 
determined by using an inverted inner tube in the dextrose broth. 
The results of the fermentation tests are given in detail in Table 1 and 
are recapitulated in Tables 5 and 6. The results shown in the two 
latter tables are given graphically in figures 4 and 5, in which the 
frequency of occurrence' of cultures forming certain arbitrary amounts 
of acid is platted. 



FEBMENXATION OF CABBOHYDRATES. 



23 



Table 5. — Fermentation of test snbstances by liquefying cultures. 



Test substance. 



Dextrose: 

N umber of cultures 
Per cent of total... 

Lactose: 

N umber of cultures 
Per cent of total... 

Saocharose: 

Number of cultures 
Per cent of total... 

Glycerin: 

N umber of cultures 
Percent of total... 

Mannite: 

N umber of cultures 
Per cent of total... 

Oalactoee: 

Number of cultures 
Per cent of total. . . 

Rafflnose 

Number of cultures 
Per cent of total... 

InuUn: 

Number of cultures 
Per cent of total. . . 



Per cent of lactic acid. 



8 

■ 

o 



1 
3.45 




21 
63.6 

25 
75.8 

22 
66.7 

17 
53.1 

31 
100 

22 
95.6 



s 



4 

13.8 

12 
36.4 

1 
3.0 

2 
6.1 

1 
3.0 

4 

12.5 



d 



5 
17.2 

11 
33.3 

3 
9.1 

1 
3.0 

2 
6.1 

5 
15.6 








2 
8 



12 
41.4 

, 4 

12.1 




4 
12.1 

3 
9.1 

3 
9.4 



2 
3 



1 

3.45 

2 
6.0 

5 
15.1 




3 
9.1 

2 
6.3 











3 
9.1 

1 
3.0 

1 
3.0 









2 

S3 



9 



3 
10.3 

1 
3.0 

2 

6.1 



1 
3.45 



1 
3.0 

1 
3.1 



1 
4.4 



1 
3.0 



2 

9 



s 



o 



1 

3.45 



■ 

8 



I 



3 

d 



1 
3.451 



8 

■ 

o 



•B 



o 



29 



33 



33 



33 



33 



32 
31 



Table 6. — Fermentalion of test substances by nonliquefying cultures. 





Per cent of lactic acid. 


Test substance. 


i 

d 

1 

1 

0.9 

3 
2.6 

75 
64.1 

93 
78.2 

78 
67.2 

8 
6.8 

90 
78.9 

101 
86.3 


• 
■ 

2 

s 

d 




5 
4.3 




2 
1.7 

1 
0.9 

5 
4.2 








i 
i 

d 

2 
1.7 

5 
4.3 




12 
16.8 




8 
6.8 

1 
0.9 





• 

i 

i 


i 


i 


• 

2 

d 


i 

I 

d 


2" 

9 

• 

O 

10 
8.6 

1 
0.8 

7 
5.9 


o* 

12 
10.3 




15 
12.8 


§ 

i 


i 

8 

d 


2 

d 

3 
2.6 


• 

o 

< 

3 
2.6 


o 


Dextrose: 

Number of cultures 
Per cent of total. . . 

Lactose: 

N umber of cultures 


4 
3.4 

6.8 

1 
0.8 

7 
5.9 

3 
2.6 

19 
16.1 

1 
0.9 

2 
1.7 


10 
8.6 

16 
13.7 

2 
1.7 

4 
3.4 

4 
3.5 

28 
23.7 




9 
7.7 


12 
10.3 

17 
14.5 

1 
0.8 

1 
0.8 

4 
3.5 

20 
16.9 




5 
4.3 


30 
25.9 

25.6 

3 

2.6 


13 
11.2 

31 
26.5 

8 
6.8 


11 
9.5 




3 
2.6 


5 
4.3 

1 
0.8 

1 
0.8 


116 
117 


Per cent of total. . . 








Saocharose: 

Number of cultures 
Per cent of total. . . 


1 
0.8 

• 


1 


117 


Glycerin: 

Number of cultures 




119 


Per cent of total 










r 










Mannite: 

Number of cultures 


3 
2.6 

16 
13.6 










11 
9.3 

1 
0.9 


1 
0.9 

1 
0.8 

1 
0.9 


11 
9.5 

1 
0.8 





11 

9.5 

1 
0.8 

1 
0.9 






• 


116 


Per cent of total. . . 










Galactose: 

Number of cultures 








118 


Per cent of total... 
RaflSnose: 

Number of cultures 

Per cent of total. . . 
Inulin: 

N umber of cultures 


12 
10.5 


7 
6.1 


1 
0.9 


■ • • • « 

114 
117 


Per cent of total. . . 







































We have reckoned auy acidity of below 0.1 per cent as no 
fermentation, although this may be an arbitrary distinction. 

In the work by Winslow previously cited the frequency curves 
usually showed three modes. In his work, however, a larger num- 
ber of cultures selected from various sources waa used, while ours 



24 OLABSIPYIITO LACTIC-ACID BACTEBIA. 

came from milk only. Our curves usually show only two modes, 
one at thfl point of no fermentation and one at a point of acidity 
varying with the different test substances. There are, however, 
' certain differences in the curves of the liquefiers and the nonliquefiers. 
The dextrose curve for the liquefiers shows that a lai^e proportion 
form 0.2 to 0.25 per cent of acid, with a smaller nimiber at 0.35 to 



ri?^r'ar5r> 8 t 



.^^w>ss 



"U 



— ajKCM4)iose 



^jfc\- 



: «* « at «r -%r 

Fla. 4.— Prequencf curves [or add lormHtlon by the llqasT^rlEif iMiltnrej. 

0.4, while with the nonliquefiera there is a high point at 0.35 to 0.4 
per cent and possibly a second mode at 0,5 to 0.6. 

With the liquefiers the other test substances show two modes only, 
Kaflinose was not fermented at all, and only one culture formed acid 
from inulin. 

The number of liquefying cultures was too small to make many 
deductions therefrom, but it ia easj to separate these cultures into 



PBBMENTATION OP CABBOHTfDRATES. 25 

two distinct groups. One of these forms a small amount (0.1 to 0.3 
per cent) of acid from dextrose, and is a micrococcus usually appeal^ 
ing in tetrads. The effect on milk is weak, and the curdling, which 
is slow, is probably due more to the action of a rennet than to the 
production of acid. This group, as represented by these cultures, is 
undoubtedly heten^neous, and by the application of these methods 



1 



Fio. t.— FraqQcmcy coma lor add lOnuatioii by the Danllqoefjrlnc mlton*. 

to a larger number of cultures would be split up in distinct sub- 
groups. The second group of liquefiers is interesting in that it 
evidently is a variation frooi the typical nonliquefying lactic-acid 
oi^anism. In its morphology it is identical with the ordinary type, 
but differs from it not only in the liquefaction of gelatin, but also 
in usually fermeutiiig glycerin. Ita action on milk is characteristic. 



26 CLASSIFYING LACTIC- ACID BACTERIA* 

The milk is curdled promptly with a firm acid curd ; digestion begins 
at once and almost always causes a separation of curd from the 
whey down the side of the tube. 

In the nonliquefying group there are with all the test substances 
only two distinct modes in the curves with the possible exception of 
mannite. In this case there are three modes, one below 0.1 per centy 
one between 0.1 and 0.35, and another between 0.45 and 0.5. 

Reference to Table 1 shows that of the 8 cultures belonging to the 
group falling between 0.1 and 0.35 per cent, 2 were gas formers and 1 
made milk slimy, while the other 5 apparently did not differ from those 
forming a high acidity or failing entirely to ferment this substance. 

In arranging these reactions on the basis of their correlations, one 
of the formulas for the expression of correlation, as, for instance, that 
of Yule, may be used, but for tins particular work the determination 
of the coefficient of correlation is not necessary. Even a casual ex- 
amination of Table 1 shows that the nonliquefiers may be separated 
into two groups, in one of which the fermentation is usually limited 
to dextrose, lactose, and galactose, with an occasional culture fer- 
menting saccharose or mannite. A second group may be formed of 
cultures in which the fermentative- ability is distinctly higher. These 
groups are illustrated by figure 6, in which each culture is placed in 
one of four groups and arranged on the positive or negative side of 
a dividing line, as the case may be, in each of the salient characters. 

The division of the nonliquefiers is not an arbitrary one, as the 
distinction between the two groups is marked. Not only is there a 
general lack of fermentative ability in Group A, but there is no cor- 
relation in the few cases of fermentation of the more difficultly fer- 
mentable substances. The fermentation of saccharose is no indica- 
tion that the culture will ferment mannite. On the other hand, in 
Group B more of the test substances are fermented and there is a 
high correlation between certain activities. The fermentation of 
raffinose is usually correlated with the fermentation of saccharose, 
mannite, and glycerin, and to a lesser degree with inulin. The high 
fermentation is also correlated with the reduction of neutral red. 

In making up these groups it was found that 6 cultures (6fl, 7aa, 
7ak, 7cq, 7dw, and 13u) did not belong in this collection, and they 
were not included in the table. It will also be noticed that 7ci, 7cg, 
and 7dm are in a transition stage between Groups A and B, either 
through the loss of properties formerly possessed or the acquisition 
of new ones. In morphology and general culture characters all of 
the numbers of this group agree with the typical lactic culture. It 
should be stated that we obtained all of the cultures of Group B from 
one locality, Albert Lea, Minn., although not from one sample. 
However, in the course of another investigation a large number of 
cultures which could be properly placed in this group have been 
isolated from Washington milk, indicating that it is widely distrib- 



II 



GBOUPINQ OP CULTURES. 



' 28 CLASSIFYING LACTIC- ACID BACTERIA. 

uted, although it does not occur in so large numbers as the Group A 
type. While the number of cultures included in Group C is too 
small to permit many positive deductions, it is evident that it rep- 
resents a type quite distinct from A and B, from which it is differ- 
entiated not only by the liquefaction of gelatin but also by the cor- 
related functions of the fermentation of mannite and glycerin and 
the failure to ferment rafiinose and inulin. These 9 cultures include 
3 differing somewhat from the others morphologically, and it is 
probable that a larger collection would allow a deeper and more posi- 
tive separation. Group D is made up of cultures which, while they 
are of common occurrence in milk, have such a low fermentative ability 
that they probably take little part in the normal souring of milk. 

CONCLUSIONS. 

The stability of the fermentation tests is made evident not only by 
the constancy of the reactions on repeated tests, but also by the 
marked correlation between different fermentative activities and 
between the fermentations and other characters. 

The usefulness of these tests is only apparent when by means of 
biometrical methods the correlations are established and the cultures 
are arranged in groups possessing certain characters in common, but 
in which minor variations from the type are not excluded. 

The test substances used can not be determined arbitrarily. It is 
probable that it will be desirable to vary the test substances used with 
different groups of bacteria. We have found raffinose and glycerin and 
the gelatin test especially valuablci while saccharose, which has long 
been used for differential tests, has much less value. All of the groups 
have many cultures fermenting this sugar, and there is little correla- 
tion with other reactions. While the determination of the fermen- 
tation of rafiGuose or glycerin gives one a good idea of the group in 
which the culture should be placed, the knowledge that a culture fer- 
ments or fails to ferment saccharose is of little assistance. 

It should be remembered that these cultures were all selected on 
the basis of the possession of a single positive character, the fermen- 
tation of lactose. If the collection had been made on a broader basis, 
it is highly probable that the cultures would have formed other 
groups around types distinct from those we have found but related 
to them by certain common characters and by transition forms. 

The results recorded in this paper are too meager to warrant any 
attempt at fixing names or establishing the place of the lactic-acid 
bacteria in the bacteriological system, but we believe that this work 
indicates that future efforts in the direction of systematic bacteriology 
should be toward the determination of those characters that are sig- 
nificant and enduring rather than in fruitless controversy over the 
priority or stability of some name based .on descriptions so undeter- 
minative that they convey no meaning. 



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2. Hastings, E. G., and Hammer, B. W. The occurrence and distribution of a 

lactic acid organism resembling the Bacillus bulgariciu of yogurt. Wisconsin 
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June, 1909. 

3. Heinemann, p. G., and Hefferan, Mary. A study of Bacillus bulfforicus. 

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4. McDonnell, Milton Earlb. tiber Milchs&ure-Bakterien. Inaugural Disserta- 

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5 . Weigm ANN , H . Versuch einer Ein teilung der Milchsfturebakterien der Molkereige- 

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6. MOller, Paul Th. t^ber die Streptokokken der Milch. Archiv fUr Hygiene, 

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7. LoHNis, F. Versuch einer Gruppierung der Milchs&urebakterien. Centralblatt 

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12. Buchanan, Robert Earle, and Truax, Roy. Noninheritance of impressed 

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13. MOller, Leo. Vergleichende Uuterauchungen ttber Milchiraurebakterien (des 

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Royal Society of London, series B, vol. 79, no. B532, pp. 329-336. London, 

June 5, 1907. 

29 



30 CLASSIFYING LACTIC-ACID BACTERIA. 

16. Ritchie, John. Notes on experimento as to the constancy of the carboyhdrate 

reactions of the streptococci. Lancet, vol. 175, no. 4432, pp. 374-376. London, 
Aug. 8, 1908. 

17. (xORDON, M. H. A ready method of differentiating streptococci, and some results 

already obtained by iti application. Lancet, vol. 169, no. 4289, pp. 1400-1403. 
London, Nov. 11, 1905. 

18. MacConkey, Alfred. A contribution to the bacteriology of milk. Journal of 

Hygiene, vol. 6, no. 3, pp. 385-407. Cambridge, July, 1906. 

19. Harding, H. A. The constancy of certain physiological characters in the classiH- 

cation of bacteria. New York Agricultural Experiment Station, Technical 
Bulletin 13. Greneva, June, 1910. 

20. Andre WBS, F. W., and Gordon, M. H. Report on the biological characters of' 

the staphylococci pathogenic for man. Great Britain, Local Government 
Board, Thirty-fifth Annual Report (1905-06), supplement containing the report 
of the Medical Officer (190W)6), pp. 543-560. London, 1907. 

21. Houston, A. C. Report on the bacteriological examination of the normal stools 

of healthy persons. Great Britain, Local Government Board, Thirty-third 
Annual Report (1903-04), supplement containing Report of the Medical Officer 
(1903-04), pp. 472-527. London, 1905. 

22. Andrewes, F. W., and Horder, T. J. A study of the streptococci pathogenic 

for man. Lancet, vol. 171, no. 4333, pp. 708-713; no. 4334, pp. 775-782; no, 
4335, pp. 852-855. London, Sept. 15, 22, 29, 1906. 

23. WiNBLOw, C. E. A., and Rogers, Anne F. A revision of the Coccacese. Science 

vol. 21, no. 539, pp. 669-672. New York, Apr. 28, 1905. 

24. WiNSLOw, Charles Edward Amory, and Winslow, Anne Rogers. The syste- 

matic relationships of the Coccaceae. New York, 1908. 

25. Henderson, Lawrence J., and Webster, H. B. The preservation of neutrality 

in culture media with the aid of phosphates. Journal of Medical Research, 
vol. 16, no. 1, pp. 1-5. Boston, Mar., 1907. 



ADDITIONAL COPIES of thispublicatioil 
-Tl. may be procured from the Supebin teitd- 
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^^\ 



60 U. S. DEPARTMENT OF AGRIQJ^LTURE, ^ , 

BUREAU OF ANIMAL INDUSTRY.— Bulletin i^. = ' 



THE INFLUENCE OF THE STAGE OF LAQATION ON THE 
COMPOSITION AND PROPERTIES OF MILK. 



BY 

C. H. ECKLES, 

I^/essor of Dairy Huibandry, I 'iiiveriity of MiistMiri, 
AND 

ROSCOE H. SHAW, 
Oiemisi, Daity Division, Bureau o/ Animal Industry. 



( 



btned JuiiuuT lo. it 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL IN pUSTRY.— Bulletin 155. 

A. D. MELVIN. Cnv or Binuu. 



THE INFLUENCE OF THE STAGE OF LACTATION ON THE 
COMPOSITION AND PROPERTIES OF MILK. 



BY 

C. H. ECKLES, 

Pro/eaor of Dairy Husbandry, University of Missouri, 

AND 

ROSCOE H. SHAW, 

Oiemist, JDaity Division, Bureau o/Auimal Industry, 



I 



THE BUREAU OF ANIMAL INDUSTRY. 



Chief: A. D. Melvin. 

Assistant Chief: A. M. Farrington. 

Chief Clerk: Charles C. Carroll. 

Animal Husbandry Division: Georob M. Rommel, chief. 

Biochemie Division: M. Dorset, chief. 

Dairy Diviiion: B. H. Bawl, chief. 

Meat Inspection Division: Bics P. Steddom, chief. 

Field Inspection Divisum: R. A. Ramsat, chief. 

Pathological Division: John R. Mohler, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: E. C. Schrobder, superintendent. 

Editor: Jambs M. Pickens. 



LETTER OF TRANSMITTAL. 



U. S. Department op AaRiouLTUBS, 

Bureau op Animal Industry, 
WasUnffUm, D. C, June 29, 1912. 

Sm: I have the honor to transmit, and to recommend for publica- 
tion in the bulletin series of this bureau, the accompanying manu- 
script entitled " The Influence of the Stage of Lactation on the Com- 
position and Properties of Milk/' by Prof. C. H. Eckles, of the Mis- 
souri Agricultural Experiment Station, and Mr. Roscoe H. Shaw, of 
the Dairy Division of this bureau. The experimental work herein 
described forms a part of the investigations concerning milk secretion 
which are being conducted at the Missouri station in cooperation 
with this bureau. 

There is a considerable amount of data available bearing upon the 
lactation period of cows and the effects on the composition of the 
milk, but as a rule such investigations have been confined to a single 
constituent of the milk, usually the fat. No record coidd be foimd 
of any investigation with controlled animals where all or even a 
majority of the milk constituents have been studied diuing a com- 
plete lactation period. Accordingly it was deemed advisable to 
undertake the present work so as to cover this point satisfactorily. 
The cooperative work mentioned has been in progress for about six 
years. Investigations regarding the influence of other factors con- 
cerning milk secretion are also under way and will be reported Ifiter. 

The authors desire to acknowledge their indebtedness to Messrs. 

A. E. Perkins, J. O. Halverson, and J. C. Payne, formerly of the 

Dairy Division, for assistance rendered in compiling the data in this 

bulletin. 

Respectfully, A. D. Melvin, 

Chief of Bureau. 
A Hon. James Wilson, 

Secretary of Agriculture. 

3 



CONTENTS. 



Page. 

Intioduc tion 7 

Previous invefltigatioiis 8 

The present experiments 18 

Puipose and plan of the investigation 18 

The feed ration 19 

Method of sampling and preparation of samples for analysis 21 

Methods of analysis 22 

Results of the experiments 24 

Total nitrogen and protein 32 

Casein nitrogen and casein 42 

Albumin 46 

Residual nitrogen 47 

Ratio of protein to other constituents 48 

Fat 49 

Relation of fat to other constituents 50 

Sugar '. 52 

Total solids 63 

Relative size of hi globules 55 

Melting point 57 

Refractive index 59 

Reichert-Meisal number 59 

lodin number 62 

Saponification 64 

Ash 65 

Additional data from five Jersey cows 67 

Effects of maintaining the animals at uniform weight 70 

Possible variations due to the ration 70 

Effect of keeping the cows fanow 70 

Gleneral discussion of the results 71 

Relation of stage of lactation to use of milk as food 72 

Relation to churning r 73 

Abnormal taste in milk at end of lactation period 73 

Summary 76 

Appendix—Table 1 78 

6 



ILLUSTRATIONS. 



Page. 
FiQ. 1 . Diagram showing variation in yield and composition of milk of cow 

No. 4 at end of each 4-week period 33 

2. Same for cow No. 99 33 

3. Same for cow No. 118 34 

4. Same for cow No. 205 34 

6. Same for cow No. 206 35 

6. Same for cow No. 209 36 

7. Same for cow No. 300 37 

8. Same for cow No. 301 37 

9. Same for cow No. 400 38 

10. Same for cow No. 402 38 

11. Same for cow No. 403 39 

12. Diagram showing variation in yield and composition of milk at end of 

each 4-week period; average for 11 cows 39 

13. Relative size of fat globules as influenced by stage of lactation 55 

14. Variations in fat characters at end of each 4-week period 60 

6 



THE INFLUENCE OF THE STAGE OF lACTATION ON THE 
COMPOSITION AND PROPERTIES OF MILK. 



INTRODUCTION. 

It is a weU-knoDipi fact that although the same constituents are 
always present in milk, the relative amounts of each are subject to 
constant variation. These variations in composition are known to 
be injBuenced by a number of causes, lunong which are (1) the breed 
of the animal, (2) the individuality, (3) to some extent the feed, (4) 
the interval between milkings, (5) the various stages in the period of 
lactation, (6) more or less by the health of the animal and by tem- 
perature and weather conditions. It is also known that the fore 
milk and the milk last drawn differ in composition, and that some 
variations occur between morning and evening milkings. A large 
number of observations are recorded regarding these variations and 
their causes, mostly, however, in connection with the fat alone. 
The data regarding certain of these factors are consistent and con- 
clusive, but concerning others they are conflicting and insufficient to 
justify general conclusions. The main criticisms to be made regard- 
ing the large amount of data that has been published along these 
lines is that in most cases only the per cent of fat was taken into 
account and that the animals supplying the samples were not prop- 
erly selected and controlled. 

In 1906 an agreement was entered into between the Missouri Exper- 
iment Station and the Dairy Division, Bureau of Animal Industi^, 
United States Department of Agriculture, for a series of investiga- 
tions, the main object of which was to be a further study of the 
factors influencing the composition and properties of normal milk. 
In beginning such a line of investigation it was decided that it would 
be necessary to repeat much of the work that had been done in the 
past, but imder more carefully controlled conditions, in order that 
results might be more definite. There are a number of questions that 
have to be considered in planning all such investigations regarding 
the selection of suitable animals to furnish the samples. Among the 
questions that always arise in this connection are the three following: 
The effect of the stage of lactation, the influence of the breed, and the 
individual variations. The logical plan in beginning such a series of 

7 



8 STAGE OF LACTATION AND PBOPEBTIES OF MILK. 

investigations as was contemplated seemed to be first to supply fur- 
ther data on the effect of the three factors mentioned. The data at 
the same time would serve as a basis for the planning of future work 
regarding the influence of other factors. 

Since the various stages in the period of lactation represent a factor 
always to be taken into account and one known to have an important 
bearing on the composition of milk, plans were miade to begin these 
investigations with this as the first main objective point. The plans 
were so arranged that the same data would also add to our knowledge 
regarding the influence of the other two factors, i. e., the breed and 
individuality of the animal. 

In this publication the influence of the stage of lactation alone is 
considered. The data regarding the ixifluence of breed and indi- 
viduality of the animal are to be published in the near future. 

PREVIOUS mVBSTIGATIONS. 

There is a mass of data available which has a connecuoji either 
near or remote with the influence of the stage of lactation on the 
chemical composition of milk. The advent of the Babcock test in 
1890, which offered a rapid and simple method for the determination 
of fat, lent a stimulus to such investigations. As a whole the inves- 
tigations along this line which have been published have been limited 
to a single constituent of milk, usually the fat. In but few cases has 
any attempt been made to eliminate the influence of the feed of the 
animals, and there is no record of any investigation on controlled 
animals where all or even a majority of the milk constituents have 
been studied during an entire lactation period. 

No purpose would be served by giving a complete list of the works 
published on this subject. From a laige number of references the 
following have been selected as representing the more important 
investigations having to do with the influence of the stage of the 
lactation period on the chemical composition of milk: 

Schrodt and Henzold ^ in 188^1891 conducted a series of investiga- 
tions on the composition of butterfat and its variation as influenced 
by the period of lactation, feed, etc. The first investigation was 
conducted with mixed milk from a herd of 10 cows of Angler, Brieten- 
burg, and Shorthom-Dithmarschen breeds and with milk from an 
individual Angler cow. The second investigation was conducted 
with the mixed milk from a herd of 220 cows of Angler and Ayrshire 
breeds. The cows were not kept on a uniform ration. In both 
investigations they were stall-fed in the winter and put out to 
pasture during the sununer months. Samples were taken from the 
one Angler cow every day for the first 16 days after calving, then every 

1 Schrodt, U..f and Heoiold, O. UntenadimigBn tod But t artetL Die Landwirtaohaftllchen Vecsochs- 
Stetioiien. VOL 38, p. 340-871. Balin, 1801. VoL 40, p. 200-300. Berlin, 1802. 



PREVIOUS INVESTIGATIONS. 9 

3 or 4 days till the end of the lactation period. The samples of 
herd milk in both investigations were taken twice weekly. The 
milk was skimmed, churned sour, the butter melted, and the clear 
fat filtered off. Determinations were made on the samples from 
the individual cow of volatile acids, iodin number, and the refractive 
index. On the mixed milk the same determinations were made 
and in addition the determination of the insoluble acids. In the 
case of the mixed milk the stage of the lactation period was found 
by averaging the lengths of the periods that the individual cows 
had been in lactation. In all of the investigations the course of 
the variation of the different constituents was practically the same 
through the lactation period. The following conclusions were 
reached: 

In the first milkings the percentage of volatile acids in the fat is very low, but it 
rises rapidly in the first few days to a maximum value. Then it remains stationary 
for about 2 months, after which it declines steadily until the close of the lactation 
period. 

The content of olein as shown by the iodin number constantly decreases during 
the lactation period. 

In the latter part of the lactation period the percentage of insoluble acids is higher 
than in the first part 

Aa a rule the decrease in the volatile acids is accompanied by an increase in the 
refractive index. 

Apparently the composition of the butterfat bears a close relation to the stage of 
lactation, but none to changes from stall feeding to pasture feeding. 

Klein and Kirsten ^ in 1901 and 1902 conducted an investigation 
on individual samples from five cows to find the effect of age of the 
cows and of the stage of lactation on the composition of the butterfat. 
The cows selected were of different ages. Three were old cows, 
aged respectively 13, 9, and 8 years. Two were 3-year-old cows. 
All of the cows were given the same feed, but the feed was not 
uniform throughout the lactation period. Samples were taken at 
intervals of approximately one month. The determinations included 
the Beichert-Meissl number, Koettstorfer number, Hehner number, 
Hubl number, and refractive index.' Curves were plotted from 
the results and the following variations due to the period of lactation 
shown: 

The Reichert-Meissl number showed a gradual decrease throughout the lactation 
period. 

The Koettstorfer number followed approrimately the same variations as the Reich- 
ert-Meiaal number. In two cows it rose near the end of the period. 

The curve lor the Hehner number rose during the entire period. It showed varia- 
tions which were in the opposite direction to those of the Reichert-Meissl number. 

> Ktoin, 7., and Klistao^Artliur. Untemichung Ober die chftrntachft Za8ammeoaetsimg.de6 MilchliBttes 
fiimJhnfr Kfihe von veraehiedeDem Altar im Lauls elner Laktotion. HUch Zeltnng, toL 31, no. 37, p. 
£77-678, Sept. 13; no. 38, p. 604-606, Sept. 20; no. 30, p. 611-«13, Sept. 27. Leipsic, 1008. 

> For tlia metliods osed in these detenninations see footnote on page 22. 



10 STAGE OF LACTATIOK AND PROPEBTtES OP MILK. 

In general the Hubl number showed a rise with the period of lactation, but in 2 
cows there was a decline near the end of the period . The authors ascribe this variation 
to a change in the feeding. 

The refractive index showed the same variations as the Hubl number. 

There were many minor variations which were thought by the authors to be due 
to difference in feeding. 

Penny, * of the Delaware Agricultural Experiment Station, secured 
some data on the effect of the stage of lactation on the composition 
of milk from testing the large herd of a Delaware dairyman. Three 
series of tests were made, each series covering 5 consecutive days, 
the series being located along the course of lactation as follows: The 
first, 2\ months after calving; the second, 6^ months; and the third, 
10^ months. 

From these Prof. Penny concludes that the quantity of milk 
decreases more or less gradually, and the quality increases in nearly 
the same ratio, as the lactation period advances. 

Ilinchcliff ' at Leipsic in 1901-2 conducted a careful investiga- 
tion, which included among other factors the influence of the stage 
of lactation on the chemical composition of milk. His laboratory 
work is so thorough that it is to be regretted that the number of 
animals was so limited and his data concerning them so uncertain. 

He studied the milk from 3 cows, one of these from the third 
week of the lactation period to the end and another from the seventh 
month of the lactation period to the end. Data concerning the 
condition of the third were lacking, but he states that she was appar- 
ently fresh when the study was commenced. The study of the 
third cow was also carried on to the end of the lactation period. He 
took samples from each milking for 5 or 6 successive days, which 
length of time he calls a period. These periods, with but few inter- 
vals, succeed each other during the whole lactation period. Analyses 
were made of each sample and averages calculated to represent 
the period. No attempt was made to feed the cows on a uniform 
ration, but a record was kept of the feed given them. 

He found that the greatest variations were in the fat, followed 
by sugar, protein, and ash in the order mentioned. An increase 
or decrease in the fat content of the milk was usually accompanied 
by a similar change in the fat content of the milk solids, but by an 
opposite change in the percentage of protein and sugar in the milk 
soUds. The ash content of the solids not fat was practically con- 
stant. Variations in the content of the solids not fat read inversely 
to the variations in the protein content. In general the percentages 
of fat, protein, and ash increased with the progress of lactation. 

1 Penny, Charles Ljrndall. Herd-testing. Delaware Agricultural Experiment Station, Tenth Annual 
Report, p. 15^197. Wilmington, 1896. 

• Hinchcliff, Joseph Henry. Die t&glichen Schwankungen im Gehalte der KuhmUcb an den eintehien 
Bestandteilen im Vorlaufe der Laktation. MitteUungen des Landwirtachaftlichon Institutes der Uni- 
veistt&t LeipEig, No. 6, pp. 1-112. BerUn, 1904. 



PREVIOUS INVESTIGATIONS. 11 

Swaving* in 1889-90 investigated the butterfat from cows in 
various provinces in Holland with a view of establishing the limits 
of the volatile fatty acids in butter in order to distinguish pure 
butter from butter substitutes. He took samples from the different 
provinces at regular intervals for a considerable period of time, and 
concludes that at the beginning of the lactation period the percent- 
age of volatile fatty acids increases, but that it decreases as the 
period progresses. 

ScheUenberger, * in the University of Leipsic, made a study of the 
size of fat globules with reference to the different breeds and periods 
of lactation. His published tables gave figures in which he shows 
that the Jersey cow has the laigest-sized globules and the Angler 
cow the smallest. He also shows that as the lactation period pro- 
gresses the size of the globules decreases. 

Hills,' of the Vermont station, studied the results of over 100 
lactation periods of cows of many breeds, with diversified feed and 
in three geographical localities, namely, New York, Minnesota, 
and Vermont. His conclusions are given in a summary, in which 
he states: 

The average spring cow rapidly betters the quality of her milk, beginning about 
5 months after calving; the summer cow starts in as early as the third month; while 
the fall cow maintains a fairly even quality throughout her lactation period, seldom 
improving it more than 5 per cent in fat content. The percentage of solids not fat 
also is more uniform month by month in the milk of the fall cow. The percentage 
of solids not fat in the milk of spring cows seems to lessen somewhat in the summer 
time. 

The greatest monthly variation in the quality of the milk of 115 
cows was 3.11 per cent fat; the least 0.33 per cent fat. The average 
variation was 1.26 per cent fat; the average monthly variation of 
spring cows was 1.62 per cent fat; of fall cows, 1.08 per cent fat; 
of summer cows, 1.25 per cent fat. Two-thirds of the Vermont 
and Minnesota herds gave thinnest milk during the first 2 months 
and two-thirds of the New York herds during the first 4 months. 
Ninety per cent of the Vermont and Minnesota cows gave their 
richest milk after the seventh month. Sixty per cent of the New 
York cows gave their richest milk before the eighth month. 

Speir,^ at Newton Farm, Glasgow, reviewed the records of about 
400 cows that were included in the herds of members of a more or 
less local testing association, with a view of studying the changes in 

> SwsTteg, A. 7. Bftttignnpuhlfln fOr die flOchtlgeD Fettaftoren d«r nladttlftndlschea Battenortm. 
DiBLandwlrtBcfaaftIkdlflnVflEroldl84tatloIlflI^▼oL39,p Berlin, 1301. 

> ScheUenbeiger, O. Ueber die Onne nnd die Zahl der Fettka|[eiehflii in der MQdi Ton Kflhen ver- 
sciUedeDer Bassen. Hlldi Zeitong, voL 22, No. 50, pp. 817-819. Bremen, Dec. 10, 1803. 

•Hllb, Joseph Lawxenoe. Variations in milk. Vermont Agricultoral Experiment Statkni, Ninth 
Annual Report (1805), pp. 158-186. MontpeUer, 1896. See p. 158. 

* Speir, 7olm. Uilk leoorda. Tianaactiona of the Highland and Agricultural Bociety of Scotland, 
■er.6,T0l.n^pp.l8»-212. Edinbuigh, 1906. 



12 STAGE OF LACTATION AND PBOPERTIES OF MILK. 

the percentage of fat as the lactation period advanced. His scheme 
was substantially as follows: The cows were divided into groups, 
each group representing the cows which had calved within a certain 
period, usually 2 weeks. The shortest fraction of the lactation period 
was 1 week and the longest period was 14 weeks. His figures show 
that the fat content was highest during the first week and lowest 
during the fourth week, after which a gradual increase was observed. 

Dean ^ tested 6 cows for 273 days at the Ontario experiment sta- 
tion. He divided this time into 3 periods of 91 days each, and 
averaged the percentage of fat in each period. He states that he 
found no such increase in percentage of butterf at in milk as is gen- 
erally accredited to the influence of the period of lactation, there 
being an increase of but 0.17 per cent in the second period and 0.46 
per cent in the third over that of the first period. 

Cooke,' after studying the complete records of the Vermont station, 
which covered a period of several years, gives these conclusions 
regarding the influence of the stage of lactation on the composition 
of milk: 

All cowB shrink in quantity of milk as they get farther from calving. If they are 
fonow, this shrinkage in quantity is accompanied by almost no change in quality, 
even until they go dry, provided they are still farrow. If they are in calf, the milk 
increases in quality as it decreases in quantity; this increase is sligjit— but one- 
twentieth during the first 6 months after calving^-but becomes quite pronounced 
just before the cow goes dry. 

Cows that calve in the spring give on the average more milk during the first 3 months 
after calving than those that calve in the fall. For the seventh, eighth, and ninth 
months this is reversed. Fall cows show smaUer variations in the quality of the 
milk than cows that calve in the spring. The milk of a cow for the first few days 
or weeks after calving is very variable in quality. On the average, it is thinnest 
just after calving, becomes slightly richer during the next 2 weeks, and then holds 
almost uniform in quality for the next 4 or 5 months. 

Just after calving the milk is poorer in fat and in solids not fat than just before 
the cow went dry. The average drop in fat is 1.13 per cent, the greatest change 
being 2.35 per cent and the least 0.49 per cent. The average change in solids not 
fat is a fall of 0.47 per cent, with variations from a decrease of 1.04 per cent to an 
increase of 0.42 per cent. 

Pingree,* of Pennsylvania, has published some literature on this 
subject. The extent of the data on which his deductions are based 
may be indicated by using the author's own language: 

In cooperation with the Dairy Breeders' Association and in connection with the 
advanced registration of dairy cows, the station has made the official examination of 
about 1,500 milk samples representing the product of 128 cows from 11 herds. 

1 Dean, Henry Hoahel. Record of our dairy herd. Ontario Agrfcoltaial CoUega and Experimental 
Farm, Serenteenth Annual Report (1891), pp. 173-175. Toronto, 1802. 

> Cooke, Wells Woodbridge. Variations In quantity and quality of milk. Vennont Agricultural Ex- 
periment Station, Sixth Annual Report (1802), pp. 90-119. Burlington, 1803. See p. 90. 

* Pingree, M. H. Report of the composition of milk from herds competing for advanced registration. 
PennsylT^^nia Agricultural Experiment Station, Annual Report (1905-1906), part 2, pp. 5i-M. Harris- 
burg, 1906. See p. 54. 



PEBVIOUS INVESTIGATIONS. 13 

The author's conclusions in summary may also be given in his 
own words : 

The percentages of butterfat showed, on the average, a tendency to increase through- 
out the entire lactation period, but the increase was most marked during the first 
6 months and the last month. The percentage of solids not fat decreased somewhat 
as the lactation period advanced. 

Linfield ^ prepared 2 tables from Utah data which are calculated to 
indicate in some measure the character of changes m the composition 
of milk that are due to the advance of the period of lactation. Twelve 
cows were used in this investigation. They were nearly all ordinary 
grade animak. The lactation season in each case was divided into 
periods of 4 weeks each, beginning 3 weeks after calving. The 
author's summary is substantially as follows: 

The decrease in milk and hi yield is fsaxly constant and averages about 9 per cent 
decrease each period of 4 weeks. 

The yield of butter fat does not decrease as rapidly as the milk, due to an increase in 
the percentage of fat in the milk as the period of lactation advances. 

The percentage of &t in the milk decreased slightly for the second period and then 
gradually increased till the ninth month. For the ninth, tenth, and eleventh months 
the test remained practically stationary and increased again for the twelfth month. 

On the average the cows gave the richest milk at the end of their lactation period. 
An examination of the yearly record ehows that a few cows for 1 year gave poorer milk 
when they went dry than when fresh, but in no case where the average of 2 or more 
years was considered do the cows depart from the average result. With some the 
increase in per cent of fat was much greater than with others. 

Farrington,' when chemist to the Illinois experiment station, con- 
ducted an investigation with 6 animals for the purpose of throwing 
light on the influence of the stage of lactation on the chemical com- 
position of the milk. The investigation, which was conducted through 
an entire lactation period, consisted of daily determinations of the 
weight of the milk, percentage of fat, percentage of total solids, and 
percentage of solids not fat. The animals represented 3 breeds, 
namely, Jersey, Holstein-Friesian, and Shorthorn. The feeding 
varied considerably during the investigation. Prof. Farrington'^ 
conclusions in his summary are: 

The butter bit was the most changeable constituent of the milk. The percentage of 
solids not fat was quite imiform. Both were higher in the last part of the period of 
lactation than in the first, when the cows were fresh and the maximum quantity of 
milk was produced. This was especially true of the fiat. As the activity of the milk 
glands gradually declines until the flow of milk ceases, the formation of the fat seems 
to hold out better than the other constituents of the milk. A gradual increase of the 
grain feed from 12 to 24 pounds a day per head, and the change from stable to pasture 
feed, each increased the yield of milk, but had very littie, if any, effect on its quality. 

> Linfleld, F. B. Experiments with dairy oows. Utah Agricaltaxal Experiment Station BuL es. 
Logan, June, 190a 

* Fardngton, Edward Holyoke. Variations in milk. Illinois Agricoltural Experiment Station Bull. 24. 
QianiDaictt. 18B3. 



14 STAGE OF LACTATION AND PBOPEBTIES OF MILK. 

Simon ^ in 1900 started an.investigation of the effect of the stage of 
lactation on the proteids of milk. Two cows were used, one a Fliesian 
and the other a grade of Simmental Dithmarschen strain. One 
of these cows was on a constant ration, but the feed of the other was 
changed several times. The lactation periods were prolonged owing 
to the fact that the cows did not become pregnant until late in the 
period. At the end of the first year the work was continued by 
Trunz.« 

Analyses were made on samples from each mUking during the 
colostrum period and afterwards on composite samples of one day's 
milk taken at weekly intervab. The analyses were confined to weight 
of milk, specific gravity, fat by Qerber's method, total solids, total 
nitrogen-containing substances, total proteids, casein, albumin and 
globulin, and residual nitrogen. The total nitrogen was determined 
by the Kjeldahl method. The total proteids wero determined by 
precipitation with tannic-acid solution. The casein was determined 
by the Schlossman potash-alum method. The combined albumin 
and globulin were determined by precipitation with tannic-acid 
solution in the filtrate from whidi the casein had been removed. 
The residual nitrogen was determined in the filtrate from the total 
proteid determination by the Kjeldahl method. 

In his conclusions Trunz stated that the milk production reached 
its highest point several weeks after calving and then sank slowly and 
regularly to the end of the lactation period. The specific gravity 
followed the opposite course. The total solids and fat content 
started high, then sank until the third or fourth month, when they 
remained approximately constant for a time, and then rose to the 
end of the lactation period. 

Excluding the colostrum period, the total nitrogen content remained 
practically constant for 6 or 7 months. It then rose gradually until 
it almost doubled its average value at the end of the lactation period. 
.The total proteid content followed closely the total nitrogen content. 
Excluding the colostrum period, the relation of the percentage of 
casein to the percentage of albumin and globulin showed no decided 
variation, though the ratio of casein was much higher in the case of 
one cow than with the other. The residual nitrogen was high in the 
colostrum period, but did not suffer any material change. 

Hittcher,' in 1890-91, conducted a series of investigations on 16 
purebred Holstein (HoUandischen) cows, lasting through an entiro 
period of lactation. This was a continuation of the work of Dr. 

1 Sinum, Oustav. Bdtrag sor Kenntnifls dor EiwelaBkOrper der Kidunlloli. Z«it8clirift fOr Physlolo- 
giflcbe Gbemto, toL 33, No. 5/6, pp. 466^641. BtrasbanK, Oct. 81, 1901. 

s Trans, August, u ber die Bchwankungen der Eiweisutoffe der Kuhmilch Im Verteafe einer Laktatlon. 
Zeltschiift fOr Physlologlaotae Cbemle, vol. 39, No. 6, pp. 390-305. Stmsbaig, Sept. 19, 1903. 

s Hittcher, EarL Untersoohung der MUch von sechsmhn KQben. LandwlrtbsQhaftlioher Jalirbiicher, 
YOL 28, pp. 873-967. Berlin, 1894. 



PBEVIOUS INVESTIGATIONS. 15 

Flftiflchmann, the results of which were published in 1891,* with the 
difference that the investigations were begun at the beginning of 
lactation and not after lactation was already in progress. 

Sixteen registered cows which calved at about the same time were 
selected for the tests. Except for minor differences, the cows were 
all given the same treatment and feed, but they were not kept uncfer 
the same external conditions nor on the same feed during the entire 
period of lactation. In several cases where there was some change 
in conditions there was a noticeable change. in the composition of 
the milk. 

After each milking the milk was weighed and an average sample 
was taken. The specific gravity of this sample was taken with a 
standardized lactometer (Senkwaage) 3 hours or more after the 
milking, and the percentage of fat was determined by means of a 
De Laval lactocrit. From these results an average for each month 
was computed. From these averages the percentage of total solids 
and the specific gravity of the total solids were computed by means 
of Fleischmann's formula. Then from the above results were com- 
puted the percentage of solids not fat and the percentage of fat in 
the total solids. Tables were then made and curves plotted from these 
results. From these the following points were noted : 

1. The fat content in 10 cows was higher at the end than at the beginning of lac- 
tation. In 3 of these the increase was slight. In 6 cows the fat content was lower 
at the end than at the beginning, and in 4 of these the decrease was quite noticeable* 
In the previous investigation the fat content had increased in all but 1 cow. This 
is partially accounted for by the fact that the previous year the investigation began 
alter lactation was in progress. There were some irregularities in the fat curve 
which were easily accounted for by changes in feed, weather, etc. 

2. The percentage of solids not fat decreased noticeably in the first weeks of lac- 
tation, then it usually made an even, slightly rising curve to the end. 

3. The total solids decreased rapidly in the first weeks of lactation and rose rapidly 
in the last weeks. In general it followed the curve of the fat content. 

4. The direction of the curve of the percentage of fat in the total solids is variable. 
It usually descends during the first weeks, then rises. In all cases there was a rise in 
the curve in September, due probably to changes in external conditions. 

5. The total milk production decreased from first to last. 

6. In every case where there was any considerable increase in milk production 
there was a decrease in she i>ercentage of fat. 

Gripenberg,* in 1889-1891, conducted a series of investigations to 
find the variation in the fat content of milk during the period of 
lactation. The cows used for the investigation were Holstein, Ayr- 
shire, Angler, and native. The Holstein cows were fed a uniform 
ration throughout the year. Individual samples and composite 

1 Fleiaelimaim, Oustav Friedrlch Wilbelm. Untersuchung der Milch von sechssehn KiUisa. Berlin, 
1891. 

* Gripenbefs, R. RedogOrelse 5fv«r yerksamheten vld Mcjeriafdelningen af FdraSksstatlonen & Mus- 
tiala iDstitat 18B2. RedogOreber fOr Landtbraksekonomlska f 5rs5k k MustlalA Landtbnik^och Mejenin- 
itftat (1802) LtodtbrukaBtyrelMiw Moddelanden, No. 3, pp. 22-^, Hel^lxi^ors, I89i. 



16 STAGE OF LACTATION AND PBOPBBTIES OF MILK. 

samples from the cows of each breed were taken weekly and fat 
determinations made with a Fjord centrifuge. It was fomid that 
there was an increase in fat toward the dose of the lactation period. 

H5gstr5m^ conducted a series of inyestigations extending over 
a period of 8 years to determine the changes in the composition of 
milk dining the period of lactation. For the investigation he used 
393 Ayrshire and native cows and obtained data from 822 lactation 
periods. Fat determinations by the Babcock method were made 
twice monthly during the period of lactation. 

It was found that, if the colostrum period be omitted^ the per- 
centage of fat is high during the first month, but soon begins to 
decrease rapidly and continues to decrease until the third month, 
when it reaches its minimum value. From there oiTit increases 
gradually, reaching its maximum value at the dose of lactation. 

Hunziker' conducted an investigation with 3 animals for the pur- 
pose of studying the effect of the stage of lactation on the moisture 
content of butter. The breed of the animals is not stated. The 
ration, which excluded such feeds as would tend to influence the hard 
or soft fats, was uniform during the entire period of lactation. His 
determinations included the total proteids, the casein, the albumin, 
and the chemical constants of the fat. 

His conclusions were as follows: 

The fresh milk drawn after calving contained as high as 13.6 i>er cent proteids with 
about equal portions of albumin and casein. At the end of the second day the per 
cent of albumin in the milk from all 3 cows had dropped to below 1 percent But 
both the i)er cent of albumin and that of casein were considerably above the normal, 
even at the fourteenth milking. Slight irregularities excepted, there was a rapid 
decrease in the per cent of albumin, casein, and total proteids during the first 7 days 
after calving, then a gradual decrease up to and including the second month, then the 
per cent remained fairly constant up to and including the fifth month. After that 
there was a gradual increase up to and including the eighth month, followed by a more 
rapid rise toward drying up. 

The Reichert-Meissl number and the per cent of soluble &tty acids were highest 
at the beginning of the period of lactation ; slight irregularities excepted, they decreased 
as the period of lactation advanced and were lowest toward the close of the period of 
lactation. 

The insoluble fatty acids were lowest at the beginning, gradually increasing during, 
and were highest at the end of, the period of lactation. 

TheiB<:t that the Reichert-Meissl number, the soluble and the insoluble &tty acids, 
bear a definite relation to one another, shows clearly that the per cent of soluble and 
insoluble acids is affected by the period of lactation, and that the soluble acids decrease 
while the insoluble acids increase as the period of lactation advances. 

The results concerning the iodin number are irregular and, considering the relatively 
small number of data, do not warrant the drawing of definite condusions as to the effect 
of the period of lactation on the per cent of olein in butter. 

i HOgstrdm, K. A. Komjdlkens fetthalt, dess nonnala v&xUngar och ftrftHghet. KungUga Landtbniks- 
Akadezniens Handlingar och Tidskiilt, toI. 45, No. 8/4, pp. 137-176. Btockfaolin, 1906. 

s HunzlkBr, Otto F. The molstare content of batter and the ftkcton which control Its variations. 
Indiana Agricoltural Experiment Station, Twenty-OcBt Annual Report (1906), pp^ 62^. Lafeiyatte, 
1900. 



PBBVIOUS INVESTIGATIONS. 17 

Perhaps the most extensive investigation concerning the effect of 
the stage of lactation on the chemical and physical composition of 
milk was conducted at the New York Experiment Station* during the 
years 1890 to 1894, inclusive. The work was done on milk from 14 
animals of Jersey, Guernsey, American Holdemess, Holstein-Friesian, 
Devon, and Ayrshire breeds. 

The object of the investigation was many-sided, including (a) the 
effect of feed on the quality and quantity of milk, (i) the effect of the 
stage of lactation on the chemical and physical composition of milk, 
(c) the relation of the several constituents of milk to the production 
of butter and cheese, (d) the suitability of the several breeds for the 
different dairy products, etc. Although careful records were kept 
of the feed given, no definite ration was fed and no attempt made to 
eliminate the influence of feed. 

The investigation covered 4 entire lactation periods, and, briefly 
summarized, the figures warrant the following conclusions: 

The milk yield decreased in every case as the period of lactation advanced. 

The felt yield followed the milk yield very closely. In general, the percentage of 
fat remained fairly constant up to the fifth month of the lactation period, then it stead- 
ily increased to the end. 

The total solids, in general, after a slight decrease during the first month, showed a 
gradual increase as the period of lactation progressed, though the rapidity and con- 
stancy of the increase varied in different periods. 

The casein suffered a slight decrease in the first month, then gradually increased up 
to about the last month, after which the increase was rapid up to the end of the lacta- 
tion period. The percentage of casein was generally higher through the first period of 
lactation than in the 3 following periods. 

The sugar was the most variable of the milk constituents. The general averages for 
aU periods showed a decrease, followed by about an equal increase up to the tenth 
month, when there was a marked decrease to the end of the lactation period. This 
does not, however, hojd true for each separate period; e. g., the percentage of sugar 
during the first lactation period tended to increase during lactation; during the 
second and third periods it foUowed the general average, while during the fourth 
period it tended to remain constant. 

The percentage of ash according to the general average remained fairly constant 
throughout the lactation period, despite a few variations according to the i)eriod. 

The physical composition depends largely upon the breed of the animal. There is, 
however, one general rule — the relative number of small fat globules steadily increases, 
with a corresponding decrease in the relative number of the large &.t globules, as the 
period of lactation prepresses. The total number of fat globules also greatly increases. 
The percentage of total small fat globules increased 68 per cent in the second period 
over the fiirst, while the largest globules decreased 67 per cent in the second period over 
the first, and at the same time the intermediate-sized globules decreased to 83 i>er cent 
of what they were in the first. There was a similar change in the third period over the 
second. The physical changes from period to period are closely analogous to the 
physical changes from month to month of each lactation period. 

iNew York Agrlcaltmal Experiment Btation. Ninth, Tenth, Eleventh, Twelfth, and Thirteenth 
Annual Beports, Geneva, 1890 to 1894. 

68223^— BuU. 155—13 2 



18 STAGB OF LACTATIOK AND PBOPEBTIBS 07 MILK. 

THE PRBSBIIT BZPBRIMBNTS. 
FUKPOSE AND FLAN OF THE INYESTIOATION. 

A review of the references made to the previous investigations 
regarding the effect of the stage of lactation will show that in no 
case were the conditions controlled to the extent of eliminating other 
possible causes for the variations found. It has been demonstrated 
that the nature of the feed has an important influence on milk, espe- 
cially in regard to the composition of the fat. For this reason it is 
not safe to conclude that certain results obtained are to be attributed 
to the stage of lactation, if the ration varies from the dry feed of 
winter to green pasture grass of summer, as has been the case in some 
investigations. In planning our investigation we attempted to con- 
trol these factors more completely. While the effect of the stage of 
lactation was the main factor under consideration, the plans were so 
made that the influence of breed and individuality could be studied 
at the same time from the data secured. Twelve animals were 
selected for the tests, as it was believed that this number would be 
sufficient to eliminate variations due to individuality of the animal 
and make it possible to draw correct general conclusions regarding 
the influence of the stage of lactation. Four breeds were selected 
in order that the relation of breed to variations caused by the stage 
of lactation could be observed and, further, that the breed character- 
istics could be studied at the same time. 

The general plan was as follows: Twelve animals were to be used, 
namely, 3 each of the Holstein-Friesian, Ayrshire, Shorthorn, and 
Jersey breeds, the animals to be as near as possible typical specimens 
for the breeds — ^that is to say, neither inferior nor superior producers 
of milk, but approximately the average, or a little above, for the breed. 
The animals used were all purebred and registered. They were fed 
and cared for throughout the entire experiment under much the same 
conditions as would be found in a commercial dairy, except regarding 
the control of the feed and animals. One of the Ayrshires reacted to 
the tuberculin test and was put out of the experiment soon after the 
b^inning. Table 1 gives the data in detail regardiog the 11 cows 
that were used throughout a complete lactation period. 

The milking was done by a student of the agricultural college, the 
precaution being taken to change milkers as little as possible. In 
most cases not more than one change was made during the entire 
milking period of the animal. 

The date of beginning the sampling for analysis was that ordinarily 
followed in practical dairies, five dhjs after the birth of the calf, if the 
cow and the milk seemed normal. The sampling was continued until 
the production of milk was reduced to the point where in a commer- 
cial dairy the cow would not be milked longer. The purpose in view 



THE PBBSENT EXPEBIMENTS. 19 

was to give these animak such treatment as they would receive in the 
hands of a practical dairyman where the product was used for market 
milk or other purposes. 

It was contemplated having the cows bred at such times as would 
usually be practiced in a conunercial dairy in order that the next calf 
might be bom at approximately a year from the beginning of the lactar- 
tion period covered by the experiment. With some of the animals the 
interval between the birth of the calves was somewhat longer and in 
others shorter, and one of the Jersey cows, No. 1 18, would not breed 
and remained farrow throughout the period covered by the investiga- 
tion. It is not unusual for this to occur with Jersey cows at the age 
of this cow and could not be attributed in any way to the ration given. 
With iAm exception the animals apparently remained in normal 
healthy condition, as shown by those indications which are usually 
taken to denote thrift and health, and they have since shown no ill 
effects from the treatment given them. The oestrum periods of the 
cows were as regular as usual while on the experimental ration, and 
the calves bom later were strong and vigorous and rather larger than 
the average for the breeds represented. 

The total yield of milk and of fat for the animals was in most cases 
somewhat less than the amount produced by them in previous lacta- 
tion periods. However, the production during the experimental 
periods was more than the average of the breeds represented, and for 
this reason it is believed that the conditions were sufficiently normal 
to make the results reliable. 

In addition to the 11 cows carried through an entire period of 
lactation, data are given of the composition throughout the lactation 
period of the milk of 5 Jersey cows used in another investigation. 
The latter differed from the 11 cows in being farrow, and they were 
not kept on a imiform ration. 

THE FEED RATION. 

The main feature of the experiment was to maintain the animals 
throughout the entire lactation period on an absolutely imiform 
ration, and at the same time keep the animals in a perfectly normal 
condition. A number of difficulties at once occur to the practical 
feeder in arranging to carry out such a plan. For iostance, it is not 
possible to select any one ration which will be ideal for all stages of 
the lactation period. In the first part, when a large quantity of 
milk is being produced, the animal requires more concentrated feed 
in proportion to the roughness for the best results than at the latter 
part, and it is the common practice to make such a distinction in 
feeding. The experienced feeder supplies his animalfl with prac- 
tically the same amoimt of roughness throughout the lactation 
period, but a larger amount of grain is fed in the early part of the 



20 STAGE OF LACTATION AND PBOPEBTIES OF MILK. 

period than toward the end. This practice in feeding arises from 
the fact that a certain amount of bulky food must be consumed by 
the cow at all times on account of the nature of the digestive appa- 
ratus. Any uniform ration to be fed throughout a lactation period 
must therefore of necessity be a compromise. This, means that in 
the early stages of the lactation period such a ration will contain 
rather too much roughness in proportion to the grain^ while at the 
latter part the reverse will be true. 

In planning for this investigation it was also necessary that a 
ration be selected that could be secured at all times throughout a 
period of two or three years required to complete the work. Further- 
more, such a ration must be palatable in order that the Am'mRUa wiH 
relish it at all times and not become tired of it. After careful con- 
sideration the ration selected for this purpose was as follows: 

Choice alfal^ hay 3 parts. 

Gniin (com, 8 parts; bran, 1 part; oats, 1 part) 2 parts. 

This ration supplied the protein and carbohydrates in approxi- 
mately the proportions found by experience to give good results for 
milk production. The amoimt of grain was made rather large in 
proportion to the hay to make siu*e that the entire ration would be 
consumed at all times. The ratio between the feeding stuffs com- 
posing the ration was kept exactly the same all the time and the 
entire amoimt fed varied in proportion to the needs of the animal. 

It would have been better had it been feasible to feed a certain 
amount of com silage during this experiment, but the probability 
that at times it would not be possible to secure this food, and further- 
more the wide variations in composition, prevented it from being 
used. The animals fared well on the ration as fed and showed no 
ill effects from lack of variety. Only a few times in carrying the 
animals through an entire lactation period were any of them ''off 
feed,'' and these animals were easily brought to a normal condition 
by giving a dose of Epsom salt. In no case was there any serious 
sickness of any kind. Two of the Ayrshire cows were fed through 
two complete periods on this same ration with no change. 

The hay, the most variable part of the ration in composition, was 
bought in large quantities from the same source in order that there 
might be but a few changes in its composition. The cows were 
housed in the manner common to this locality, by tying them at 
night in a bam for feeding and milking where the temperature was 
moderate; in the daytime they were turned outside and kept in a 
dry lot with no chance of seeming feed other than that supplied. 
They were fed twice a day, the ration for the day being divided into 
two equal parts. 



THE PB£8£KT EXPERIMENTS. 21 

METHOD OF SAMPLING AND PBEPABATION OF SAMPLES FOR ANALYSIS. 

Special care was taken that the sample which reached the labora- 
tory fairly represented the milk from the animal in question. 

The milk was weighed after milking and mixed by pouring from 
one pail to another. A sample of about 1 liter was placed in a glass 
jar bearing the number of the cow and the number of pounds of milk 
for that particular milking, and delivered to the laboratory. A cer- 
tain number of cubic centimeters per pound of milk were then meas- 
ured out and placed in a closed receptacle to make up a composite 
sample to represent a week's milk from that particular cow. The 
number of cubic centimeters per pound was regulated by the amount 
of milk yielded, and varied with the individual and the amount of 
milk produced. As the milk flow diminished, the proportion taken 
for a sample increased in order that the actual volume of the com- 
posite sample might remain to insure a quantity of fat sufficient for 
analysis. The changes in the cubic centimeters per pound taken 
were always made at the beginning A a week. Formaldehyde in 
solution as formalin was added in amounts sufficient to preserve 
the sample for the 7-day period. The amount varied from 1 part 
formaldehyde to 5,000 parts milk to 1 part to 2,500 parts, depending 
upon the season of the year. When the composite sample for the 
week was complete it was thoroughly mixed and a subsample of 
about 300 cubic centimeters taken for analysis. 

The remainder of the composite sample was heated to the proper 
temperature and the cream separated by means of a small hand- 
power separator. Since it was found the subsequent churning of 
the cream was retarded by the presence of formaldehyde, the cream 
was diluted with a quantity of warm water equal in volume to the 
skim milk removed, and again separated. The cream so obtained, 
usually about a liter in quantity, was churned by shaking in a glass 
jar of about 2 liters capacity. 

The question arose at the outset of the work as to whether the 
butterfat so obtained represented the butterfat originally in the 
milk or whether the small fat globules known to have escaped in the 
skim and butter milk were of different chemical and physical com- 
position from those which ultimately coUected as butter. On 
account of the conflicting evidence on this point it seemed advisable 
to cany on some investigation along this line before proceedmg 
further. The results of this work, which are published as Bulletin 
111, Bureau of Animal Industry, United States Department of 
Agriculture, showed that there was no difference in composition 
between the various-sized fat globules, and therefore the fat obtained 
by the above procedure may be taken as truly representative of the 
butterfat in the milk. 



22 STAGE OF LACTATION AKD PB0PEBTIB8 OF MILK. 

The butter was Immediately melted on a steam bath and allowed 
to remain in this condition until the curd and water had settled. 
Special care was taken at this point that the temperature of the fat 
did not rise above 50^ to SS'' C. and also that it remained even at 
this temperature no longer than was necessaiy.' It was then fil- 
tered through a paper filter kept warm by an electrical device and 
preserved in corked bottles which were protected from light in a 
refrigerator until analyzed. 

METHODS OF ANALYSIS. 

During the preliminary work a tendency was noticed of the sub- 
samples of milk to chum. This was particularly true of the milk 
from the Jersey cows. To avoid this the procedure was followed of 
removing the charges for all the determinations at the same time, 
including the specific gravity, the remainder of the subsample being 
stored in the refrigerator as a reserve sample. 

According to the original plan each series of determinations was 
to be made by the same chemist and this plan was followed with but 
few exceptions during the whole investigation. 

The analytical methods followed were those of the Association of 
Official A^cultural Chemists whenever possible. Duplicate de- 
terminatioiis were made in all cases, and in some cases triplicate or 
even quadruplicate Only the briefest description of the official 
method is given below. For a detailed description reference may 
be made to Bulletin 107 (revised) of the Bureau of Chemistry, United 
States Department of Agriculture.' 

Specific gravity, — ^The specific gravity was determined by means 
of a Westphal balance. 

Total nitrogen. — ^The total nitrogen was determined by the Gun- 
ning method. 

Casein nitrogen, — ^The casein nitrogen was determined by the 
official method of precipitating the casein with 10 per cent acetic^ 
acid solution and determining the nitrogen in the precipitate by the 
Gunning method. 

t Aooordbig to C. A. Brown (Annual R«port of the PennsylTanJa State CoUese, 1809-1900, p. 206) a 
temperatare much aboye liO* 0. will very soon alter the oompoaltlon of batterfat Bntterfat kept at 
fiO* 0. for two days showed a loss of over one unit tai iodin number. 

* For tbe benefit of those who may be nnlkmillar with some of the tenns the following explanation may 
be helpltil: The Beicbert-Meissl number is an arbitrary measure of the volatile acids, of whleh butyric is 
the principal one in butterlat. The figures do not show the percentages of the acid, but serve as a means 
of comparing different late with refennce to their volatile oGostitoentB. The Iodin absorption number 
Indicates relatively the amount of iodin a Cat will absorb. Since the only Catty acid fdund to exist in butter- 
Cat which has the property of absorbing iodin is oleic acid, tbe iodin absorption number shows relatively 
the amount of this &tty acid present, but, in common with the Reiohert-lielssl number, the figures do not 
represent percentages. The sapcmifioation number is tbe number of milligrams of potassium hydroxld 
required to saponify 1 gram of fat. Since the amount of potassium hydroxld required depends upon 
the mnhKqiiAT weight of the fat, the saponification number serves as an indloator of the relative peroent* 
ages of the l^tty acids of high and low molecnisr weighte present. 



THE PRESENT EXPERIMENTS. 28 

Albumin nitrogen. — ^The albumin nitrogen was determined by the 
provisional method of coagulating the albumin by heating the 
filtrate from the casein nitrogen determination and determining 
the nitrogen in the coagulum by the Gimning method. 

Total solids. — ^The total solids were determined by the official 
method known as the Babcock asbestos method, employing a hollow 
copper cylinder and woolly asbestos. 

FcU. — ^The fat was determined by the official Babcock asbestos 
method. The cylinders containing the residue from the total solids 
determination are extracted with ether in Soxhlet extractors, the 
heat being supplied by an electrical device. 

Sugar. — ^The sugar was determined by the official optical method, 
using acid merciuric nitrate as the defecating agent and a Schmidt 
and Haensch half-shadow polariscope. 

Relative size offai globules *---The relative size of the fat globules 
was determined by the Babcock capillary tube method. A ^inch 
objective and 1-inch ocular provided with a micrometer were 
employed. The value of each division of the micrometer scale is 
0.00258 millimeter. This method is described in detail in Bulle- 
tin 111, Biureau of Animal Industry, United States Department of 
Agriculture. 

MelHng point of the bvMerfat. — ^The melting point was determined 
according to Wiley's method, by placing a disk of the fat in a large 
test tube containing boiled distilled water and boiled alcohol which 
had been cooled, the tube being placed in a beaker of water which 
was slowly heated, and noting, by means of a thermometer grad- 
uated to 0.1^ C, the temperature at which the disk assumed the 
form of a sphere. 

Refractive index of the hiMerfaL — ^The refractive index was deter- 
mined with a Zeiss-Abbe refractometer which had been standardized 
with distilled water. The fat was kept at a constant temperature 
above its melting point during the determination by means of a 
current of warm water circulating through the instrument. The 
reading was reduced later by means of a factor to 25^ C. 

VolaJtUe acids of the butterfat. — ^The method of Reichert, modified 
by Meissl, was employed in the estimation of the volatile acids, 
and the residts are given as Reichert-Meissl numbers. In sappni- 
ying, use was made of the Leffman-Beam method, in which the 
fat is saponified in a flask over a naked flame with a mixture of a 
strong aqueous solution of caustic soda and pure glycerol. The 
soap obtained in this way is decomposed by sulphuric acid and 
the liberated volatile acids are distilled over with the steam and 
titrated with decinormal bariimi hydroxid solution. 

SaponificaHon value of (he butterfat. — The saponification value, or 
Eoettstorfer number, was determined by the regular official method. 



24 STAGE OP lACTATION AND FROPEBTIEB OF MILK. 

The fat is saponified in a flask on a steam bath with an alcoholic 
potash solution, using a long glass as a reflux condenser. 

lodin ahscrption number of the huMerfat. — ^The method of Hubl 
was employed in this case. The fat is dissolved in chloroform and 
subjected. to the action of a mixture of an alcoholic solution of 
iodhi and of mercuric chlorid in a dark place for 3 hours, at the 
end of which time the unabsorbed iodin is determined by titrating 
with standard sodium thiosulphate solution. The percentage of iodin 
absorbed by the fat is expressed in the results as the iodin number. 

RESULTS OF THE EXPBRIMBNTS. 

in presenting the results of this investigation it was decided to 
base the discussions mostly upon tables representing periods of 
4 weeks each. All figures given for 4-week periods are the average 
of 4 analyses, each of which represents a sample made up, as before 
described, from all the milk produced in 1 week. The object in 
using an average representing periods of 4 weeks is that the weekly 
tables giving the original analjrses are too unwieldy for studying 
the general effect of the lactation period. It is believed that the 
4-week period is long enough to eliminate the daily and weekly 
variations which, as far as our present knowledge goes, are impos- 
sible to control and is at the same time short enough to illustrate 
those changes which it is the purpose of this buUetin to show. The 
original data giving the analyses of weekly samples from which 
the other tables are compiled are found in the appendix at the end 
of this bulletin. 

In general, the data are presented in two ways, one in which the 
changes in the amount of each milk coniponent during the lactation 
period may be studied, and the other in which the relation of each 
component to the others during the lactation is shown. It is the 
plan to eliminate as far as practicable references to the effect of 
breed and individuality on the chemical and physical composition 
of milk, this being reserved for another bulletin, which will oresent 
the same data in a way to illustrate especially this effect. 

Table 1 gives the general data regarding the animals used, their 
age, yield of milk and fat, date of breeding, etc. 

Table 2 gives the yield of milk and of fat for each cow by 4-week 
periods throughout the lactation period. 

Table 3 gives the total yield in pounds of the several milk con- 
stituents for each animal during the lactation period. 

Table 4 gives the true average composition of the milk of each 

cow for the entire milking period. Since both the quantity and the 
composition vaiy, a direct average from analyses made at intervals 
is often misleading. Most of the constituents increase greatly at 
the end of the milking period and at the same time the yield of 



KBSULTS OP THE EXPERIMENTS. 



25 



milk is small. A direct average, therefore, gives a figure much higher 
than would be found had all the milk been gathered and sampled 
at one time. This error is reduced to the minimum by calculating 
the total weight of each constituent by periods and dividing the 
total produced by the total milk. Whenever an average figure is 
used in this report for the nitrogen^ fat, sugar, or total sohds the 
true average is meant. In considering the physical constants of 
the fat a direct average is used, since they vaiy but little and the 
error from such an average is too small to be of any importance. 

Table 5 gives the average analysis of the milk of each cow for 
the complete lactation period by 4-week periods. 

Table 1. — Data concerning tht cows vMd, 



No. 






of 


Breed. 


Age. 


cow. 










Yn.m. 


4 


Jenny.. . . 


6 10 


00 


. ..do..... . 


8 1 


lU 


...do 


11 4 


205 


Holsteln. 


5 3 


206 


...do 


6 


200 


...do 


3 8 


;«») 


Ayrshire. 


3 8 


301 


...do 


4 8 


400 


Shorfhom 


4 4 


402 


...do 


4 11 


403 


■ • aClO* ••• • • 


6 



DaMof 
calving. 



Noy.13,1906 
Jan. 1, 1907 
Sept27,1906 
July 17, 1907 
May 31, 1907 
July 20, 1907 
Deo. 28, 1907 
8ept.27,1907 
SepU0,1907 
Oct. 18,1907 
Feb. 11, 1008 



Date of 
breeding. 



Dec. 30, 1906 
Mar. 23. 1907 
Not bred. 
Dec. 1,1907 
Sept.28,1907 
Nov.18, 1907 
Feb. 23, 1908 
Mar. 16, 1908 
Jan. 25,1908 
Dec. 21, 1907 
July 7,1908 



Period samples were taken. 



NoT.24,1907,to 
Jan. 5, 1907, to 
Oct 0,1906, to 
Jiily20,1907,to 
June 1,1007, to 
July 20, 1907, to 
Dec. 29, 1907, to 
Sept.29,1907,to 
Oct. 6, 1007, to 
Oct. 19, 1907, to 
Feb. 15, 1908, to 



• Sept. 7,1908 
Nov. 30, 1907 

• Oct. 26, 1907 
Aug. 8,190B 

>Apr. 4,1906 
Jidy 4,1908 
Oct. 3,1906 

»Sept.l9,1908 
Aug. 1,1906 
July 18, 1906 
Dec 19,1906 



Total 
yield 

of 
milk. 



Lb9, 
5,429 
6,115 
6,733 
8,684 
8,994 
8,814 
6,275 
6,382 
5,172 
4,449 
6,539 



Avei^ 
age 
fat. 



P.eu 
4.87 
4.64 
5.36 
3.24 
2.03 
3.02 
3.51 
3.85 
3.89 
4.13 
8.35 



Total 
yield 
offiit. 



Lb9. 

264.45 

284.04 

307.45 

280.76 

263.66 

273.34 

220.34 

245.64 

201.37 

183.57 

220.52 



Table 2. — Milk cmd butter/at produced by each cow, and ofveragefor each breed, by 4^week 

periods. 



Cow No. 


First 
period. 


Second 
period. 


' Third 
period. 


Fourth 
period. 


Fifth 
period. 


Sixth 
period. 


Seventh 
period. 




Milk. 


Fat. 


Milk. 


Fat. 


Milk. 


Fat. 


Milk. 


Fat. 


Milk. 


Fat. 


Milk. 


Fat. 


Milk. 


Fat. 


4 


Lb8. 

770.8 
708.9 
428.4 


Lb8, 

39.80 

37.02 


Lto. 

738.4 
090.1 
376.2 


34.18 
33.02 


667.7 
701.0 
423.9 


Lte. 
28.07 
31.05 
23.41 


Lbt. 
666.2 
628.7 
475.7 


Lb8. 

26.96 
27.62 
24.34 


Lbt. 

678.8 
618.9 
418.9 


Lb8. 

27.85 
22.41 
23.09 


Lbs. 
471.0 
550.0 
440.2 


Lbs, 
23.56 
23.21 
25.16 


Lb8. 

476.0 
400.2 
440.7 


Lbt. 

22. ao 


99 


21.37 


118 


25.67 






AveraiCB fDf 
Jefseys. . . . 


636.0 


38.41 


601.6 


33.60 


560.0 


27.61 


653.5 


26.31 


505.5 


24.45 


487.4 


23.97 


472.0 


23.15 


205 

206 

209 


788.0 
1,360.6 
1,026.1 


25.05 
41.61 
30.81 


860.8 
1,267.1 
1,086.5 


27.06 
36.62 
28.19 


827.6 
970.5 
940.9 


24.04 
25.00 
25.72 


750.4 
872.4 
818.6 


24.28 
24.79 
26.64 


742.9 
868.1 
7U.7 


24.45 
24.77 
22.22 


690.7 
773.3 
724.7 


21.12 
23.68 
20.35 


666.1 
718.5 
700.3 


21.70 
20.72 
20.60 






Average for 
Holsteins. 


1,058.2 


32.40 


1,071.6 


80.62 


913.0 


25.22 


813.8 


25.24 


770.9 


23.81 


729.6 


21.72 


605.0 


21.01 


300 

301 


837.9 
612.3 


33.53 
23.42 


871.8 
582.6 


31.37 
21.80 


869.0 
639.4 


29.36 
20.53 


778.5 
670.5 


26.18 
21.72 


741.7 
633.1 


24.60 
21.77 


738.1 
596.7 


24.04 
22.49 


676.3 
672.4 


19.08 
22.60 


Avera0B for 
Ayrdiiies. 


726.1 


28.48 


727.2 


26.50 


704.2 


24.94 


674.5 


23.95 


637.4 


23.18 


666.9 


23.27 


574.4 


20.84 


400 


680.9 
647.1 
9(19.7 


27.99 
29.44 
32.43 


662.6 
576.3 
850.8 


27.11 
24.05 
29.06 


450.6 
532.0 
820.9 


18.25 
21.13 
26.33 


501.7 
618.7 
768.1 


18.33 
19.70 
24.25 


566.9 
512.3 
681.4 


20.92 
19.68 
21.43 


588.8 
486.0 
625.9 


19.86 
19.00 
19.56 


501.2 
437.6 
569.9 


19.23 


402 


17.40 


403 


18.42 






Average for 
Shoithonis 


745.9 


20.03 


699.6 


28.74 


606.2 


21.90 


596.2 


20.76 


586.5 


20.68 


550.2 


19.47 


502.0 


18.35 



26 



STAGE OF LACTATION AND PROPEBTIES OF MILK. 



Table 2. — Milk and butter/at produced by each coWf and average for each breed, by J^uoeek 

period* — Continued . 



Cow No. 


Eighth 
period. 


Ninth 
' period. 


Tenth 
period. 


Eleventh 
period. 


TweUth 
perfod. 


Thirteenth 
period. 


Fourteenth 
period. 




Mnir. 


Fat. 


Milk. 


Fat. 


Hillc. 


Fat. 


Mlllr. 


Fat 


ICilk. 


Fat. 


MOk. 


Fat. 


MOk. 


Fat. 


4 


Lbf. 
446.6 
494.5 
413.3 


Xte. 

20.13 
20.70 
23.97 


Lbt, 

378.7 
4»4.1 
456.0 


Lbt, Lbt. 
17.92 454.4 
22.38 446.0 
23.68 469.3 


Lbt. 
23.48 


Lbt, 


Ut. 


Lbt. 


Lbt. 


Lbt. 


Lbt. 


Lbt. 


Lbt. 


99 


22.14 
21.04 


280.7 15.71 
446.7 21.66 


122.1 
417.8 


7.4i 
22.01 










118 


386..^ 


20.02 


160.9 


9.74 








Avenge for 
Jerseys 


451.5 


21.60 


439.6 


21.29 


456.6 


22.22 


363.7 


18.64 


270.0 


14.71 


366.3 


20.02 160.9 


9.74 


205 


640.4 
701.4 
717.0 


20.78 
20.99 
21.69 


648.1 
682.4 
711.5 


20.38 
20.42 
21.39 


598.7 
661.2 
620.3 


19.78 
17.31 
18.28 


574.4 
228.9 

477.7 


18.97 

7.75 

16.35 


446.2 


15.55 


311.6 


U.60 


139.7 


6.20 


206 




209 


273.4 


10.65 














1 




Average for 
HolsteiiLs . 


686.3 


21.12 


680.7 


20.73 


660. 1 


18.46 


427.0 


14.36 


869.3 


18.10 


311.6 


11.60 


139.7 


6.20 


300 


436.8 
631.1 


15.42 
20.90 


303.1 
566.0 


11.20 
20.77 


123.6 
587.7 


6.67 
21.03 


















301 


332.9 


14.21 


236.0 


9.30 


123.7 


£.10 












Average for 
Ayrshlres. 


483.5 


18.16 


434.6 


15.90 


366.6 


13.30 


332.9 


14.21 


235.0 


9.30 


128.7 


6.10 










400 


617.9 
392.6 
477.6 


19.32 
16.31 
16.87 


424.6 
246.9 
368.8 


17.06 
13.45 
14.17 


217.7 

99.5 

273.4 


9.01 
4.41 


103.3 


4.30 








1 




402 






1 




403 


10.94 












' ' ! 








! 








1 




Average for 
Shorthorns 


462.7 


17.17 


346.8 


14.80 


196.9 


8.12 


103.3 


4.30 

































Table 3. — Total yield of milk and milk consHttienU by each cow. 





Total 
milk. 


Total 
solids. 


Fat. 


Nitrogen. 


Sagar. 




Cow 
No. 


Total 
nitro- 
gen. 


Protein 
(NX 
6.38). 


Casein 
nitro- 
gen. 


Casein 
(NX 
6.38). 


Albu- 
min 

nitro- 
gen. 


Alba- 
min 

(NX 
6.38). 


Resld- 

ual 
nitro- 
gen. 


Aah. 


4 

99. ... 
118... 
205... 
208... 
209... 
300... 
301... 
400... 
402... 
403... 


Lbt. 

5,430 

6,115 

5,733 

8,68.5 

o, 994 

8,815 

6,276 

6,382 

6,171 

4,449 

6,540 


Lbt. 
764.6 
82L5 
85a5 
1,042.7 
064.1 
997.1 
757.9 
811.5 
676.2 
599.0 
796.0 


Lbs. 

264.5 

284.0 

307.5 

280.8 

283.7 

273.3 

220.3 

245.8 

201.4 

183.6 

22a5 


Lbt. 
31.5 
3L4 
35.7 
40.9 
38.1 
44.3 
30.6 
33.3 
27.6 
24.3 
33.6 


Lbt. 

200.7 

200.4 

227.6 

260.8 

243.0 

282.8 

195.1 

212.4 

175.8 

155.3 

214.6 


Lbt. 
25.2 
25.4 
28.2 
33.5 
29.8 
34.8 
25.9 
27.8 
22.4 
19.9 
28.8 


Lbt, 

160.7 
162.4 
179.8 
213.9 
19a 4 
221.9 
164.9 
177.2 
143.0 
120.9 
17a 7 


Lbt. 
3.6 
2.4 
8.7 
2.9 
8.1 
3.9 
1.8 
2.4 
2.4 
2.1 
3.2 


Lbt. 
19.5 
16.3 
23.6 
18.6 
19.6 
24.8 

n.8 

15.4 
15.4 
13.2 
2a8 


Lbt. 
2.7 
8.6 
3.8 
4.5 
6.2 
6.6 
2.9 
8.1 
2.8 
2.3 
3.6 


Lbt. 

263.7 

302.8 

275.3 

438.7 

3o3. 8 

875.0 

904.6 

316.6 

200.6 

218.5 

326.0 


Lbt. 
88.0 
46.3 
42.4 
66.4 
63.0 
61.7 
4a2 
38.9 
37.8 
32.6 
46.1 



BBSULTS OF THE BXPEBIMBNT8. 



27 



Table 4. — True average composition of the milk of each cow. 



Cow 
No. 


Aver^ 

toSl 
9oUds. 


Aver- 

souds 
not fat. 


Avor- 

toSl 
nitro- 
gen. 


Aver- ' 
age 
pro- 
tein. 


Aver- 
age 
ca<)eln 
nitro- 
gen. 


Aver- 
age 
casein. 


Aver- 

albu- 
min 

nitro- 
gen. 


Aver- 

alSa- 
mln. 


Aver- 

reSd- 
ual 
nitro- 
gen. 


Aver- 
age 
fat. 


Aver- 
age 

sugar. 


Aver- 
aSi. 




P.U. 


P.ct. 


P,et. 


P.ct. 


P.ct. 


P.ct, 


P.ct. 


P.ct. 


P.ct, 


P.ct. 


P.ct. 


P. a. 


4 


14.08 


9.21 


a58 


3.70 


a46 


2.95 


a066 


0.350 


a064 


4.87 


4.85 


0.70 


IR7- • • • 


13.43 


8.79 


.51 


3.27 


.42 


2.65 


.039 


.249 


.051 


4.64 


4.95 


.74 


118... 


14.83 


9.47 


.62 


3.97 


.49 


3.14 


.064 


.411 


.066 


6.36 


4.80 


.74 


205... 


12.00 


&80 


.47 


3.00 


.39 


2.46 


.033 


,213 


.047 


3.23 


5.05 


.65 


206... 


10.70 


7.80 


.42 


2.70 


.33 


2.12 


.034 


.218 


.066 


2.93 


4.26 


.70 


209... 


11.30 


&20 


.50 


3.21 


.39 


2.52 


.044 


.281 


.066 


3.10 


4.25 


.70 


300... 


12.10 


8.60 


.40 


3.11 


.41 


2.63 


.080 


.188 


.051 


3.51 


4.85 


.64 


801... 


12.70 


8.90 


.52 


3.33 


.44 


2.78 


.038 


.241 


.043 


3.85 


4.96 


.61 


400... 


13.10 


9.20 


.53 


3.40 


.43 


2.77 


.047 


.297 


.063 


3.80 


5.04 


.73 


402... 


13.50 


9.30 


.55 


3.49 


.45 


2.85 


.046 


.296 


.054 


4.13 


4.91 


.73 


408... 


12.20 


8.80 


.51 


3.28 


.41 


2.61 


.040 


.310 


.042 


3.37 


4.98 


.60 



Table 5. — Average analyeis of the milk of each ooto, by i-'week periods. 

cow NO. 4. 



Foot weeks end- 
tag- 


Bpedflo 
gravity 
ofmilW. 


Water. 


Total 
solids. 


RoHdR 
notfttt. 


Total 
nitrogen. 


Cttfinln 
nitrogen. 


Albumta 
nitrogen. 


Fat. 


Sugar. 


1906. 
Deo. 22 


1.0346 

1.0330 
1.0338 
1.0340 
1.0838 
1.0337 
1.0386 
1.0327 
1.0334 
1.0338 


Per cent. 
86.87 


PercerU. 
14.13 


Percent. 
9.61 


Percent. 
0.68 

.63 
.67 
.61 
.60 
.60 
.60 
.57 
.62 
.66 


Percent. 
0.44 

.38 
.48 
.40 
.48 
.48 
.47 
.46 
.50 
.62 


Percent. 
0.069 

.056 
.057 
.067 
.045 
.031 
.064 
.061 
.062 
.063 


Percent. 
6.17 

4.63 
5.07 
4.86 
4.81 
6.00 
4.73 
4.61 
4.73 
5.18 


Percent. 
4.89 


1907. 
Jan. 19. 


4.99 


Feb. 16 








4.87 


Mar. 16 


86.66 
a'{.72 
85.86 
86.13 
86.23 
86.38 
86.43 


14.44 
14.28 
14.16 
13.87 
13.77 
13.63 
14.57 


9.61 
9.10 
8.90 
9.14 
9.41 
9.02 
9.39 


6.28 


Apr. 13 


6.12 


M^ll... 


6.00 


June 8 


4.39 


July6 


4.46 


Aoc. 3 


4.67 


Sept.7> 


4.60 







COW NO. 99. 



1907. 
Feb. 2 


1.0329 
L0327 
1.0833 
1.0826 
1.0322 
1.0314 
L0810 
L0322 
1.0828 
1.0837 
1.0343 
1.0343 








0.51 
.51 
.51 
.49 
.49 
.49 
.48 
.50 
.52 
.56 
.62 
.66 


0.42 
.41 
.40 
.40 
.40 
.40 
.39 
.40 
.42 
.46 
.51 
.53 


0.088 
.054 
.037 
.025 
.029 
.043 
.036 
.041 
.036 
.043 
.042 
.071 


5.22 
4.79 
4.43 
4.40 
4.33 
4.22 
4.36 
4.18 
4.63 
4.98 
5.62 
6.07 


4.94 


VfT^ 


86.91 
86.71 
86.85 
87.00 
87.24 
86.96 
87.19 
86.65 
85.74 
84.85 
83.92 


13.09 
13.30 
13.15 
12.92 
12.76 
13.04 
12.81 
13.35 
14.27 
15.15 
16.08 


8.72 
8.86 
8.75 
8.59 
8.54 
&77 
8.63 
8.72 
9.20 
9.54 
10.01 


5.15 


¥»«•«», , 


5.17 


Apr. 27 


5.05 


m(7 K . , 


5.04 


June 22 


4.50 


Jalj20 


4.52 


Aug. 17 


5.14 


Sept. 14. 


4.62 


Oct. 12 


6.03 


Nov. 9 


6.02 


Nov. 30 


6.61 







COW NO. 118. 



1906. 
N0V.3 




















Dec. 1 


1.0302 
1.0302 

1.0324 
1.0340 
1.0345 
L0344 
L0346 
L0341 
1.0836 
1.0340 
1.0356 
1.0861 
. 1.0856 


85.92 
85.45 


14.08 
14.55 


8.77 
&97 


0.51 
.56 

.54 
.65 
.66 
.67 
.64 
.64 
.64 
.65 
.70 
.75 
.77 


0.32 
.48 

.42 
.54 
.52 
.64 
.64 
.51 
.60 
.51 
.55 
.61 
.58 


0.081 
.061 

.057 
.074 
.071 
.049 
.057 
.062 
.060 
.062 
.065 
.061 
.062 


5.31 
5.55 

6.11 
6.51 
6.71 
6.60 
6.80 
6.17 
4.47 
4.83 
6.28 
5.48 
6.47 


4.47 


Dec. 29 


4.70 


1907. 
Jan. 26 


4.56 


Feb. 23 








4.83 


Mar. 23 


84.70 

o4. 84 

84.30 
85.21 
85.55 
85.58 
84.92 
83.90 
82.84 


15.30 
15.16 
15.61 
14.79 
14.45 
14.42 
16.08 
16.10 
17.16 


9.59 
9.44 
9.81 
9.63 
9.67 
9.65 
9.80 
10.67 
10.70 


5.21 


Apr. 20 


6.20 


May 18 


6.40 


June 15 


4.57 


July 13 

Aug- 10. 


4.73 
4.00 


Sept. 7 


4.72 


Oct. 5 


4.46 


Oct. 26* 


5.22 



L«Bt period. Ave weeks. 



s Last period, three weeks. 



28 



STAGE OF LACTATION AND PB0PEBTIE8 OF MILK. 



Table 5. — Average arudysis of the mUh of each cow, by 4^week /Mrtbcir— Continued. 

cow NO. 206. 



Four weeks end- 
ing— 


Specific 
gravity 
of milk. 


Water. 


Total 
solida. 


BoUds 
not fat. 


Total 
nitrogen. 


Caaein 
nitrogeo. 


Albninln 
nitroeen. 


Fat. 


Sugar. 


1907. 
Auk. 17 


1.0338 
1.0827 
1.0328 
1.0326 
1.0325 

1.0330 
1.0327 
1.0333 
1.0329 
1.0322 
1.0329 
l.a335 
1.0331 
1.0333 


Per cent. 
8&26 
88.43 
88.30 
88.05 
87.89 

88.23 
88.02 
87.84 
88.06 
87.89 
87.81 
87.50 
86.97 
86.58 


Percent. 
11.74 
11.58 
11.70 
11.95 
12.11 

11.77 
11.98 
12.16 
11.95 
12.12 
12.20 
12.50 
13.04 
13.42 


Percent. 
8.50 
&48 

8.68 
8.70 
&82 

8.96 
8.72 
8.92 
8.80 
8.81 
8.80 
9.01 
9.36 
9.74 


Percent. 
0.49 
.43 
.44 
.44 
.46 

.45 
.45 
.44 
.48 
.48 
.51 
.55 
.59 
.66 


Percent. 
0.40 
.35 
.34 
.36 
.37 

.88 
.37 
.37 
.88 
.30 
.43 
.45 
.51 
.57 


Percent. 
a041 
.032 
.031 
.032 
.034 

.032 
.037 
.036 
.027 
.032 
.035 
.038 
.025 
.027 


Percent. 
3.24 
8.14 
3.02 
3.25 
3.29 

8.06 
3.26 
3.25 
8.15 
3.31 
3.31 
3.40 
3.68 
3.68 


Percent. 
4.69 


SeDtl4 


4.98 


Oct. 12 


4.84 


Nov. 9 


5.18 


Dec. 7 


5.42 


1908. 
Jftn. 4 


6.37 


Feb. 1 


5.20 


Feb. 29 


4.76 


Mar. 28 


5.10 


Adt.25 


5.12 


May 23 


5.13 


June 20 


5.02 


July 18 


4.89 


Auk. 8 


4.81 







COW NO. 206. 



1907. 
June 29 


1.0294 
1.0293 
1.0294 
1.0281 
1.0295 
1.0289 
L(r2K8 

1.0291 
1.0302 
1.0316 
1.0345 


80.05 
89.90 
89.82 
89.74 
89.46 
89.27 
89.25 

89.20 

oo. Wb 

8S.10 
86.70 


10.05 

laio 
iai8 
ia27 

10.54 
10. T3 
ia76 

10.80 
11.01 
11.90 
13.30 


7.88 
7.47 
7.60 
7.42 
7.66 
7.67 
7.87 

7.80 
&02 
8.81 
9.78 


a44 

.38 
.87 
.30 
.42 
.42 
.41 

.48 
.44 

.51 
.71 


a34 
.30 
.29 
.30 
.82 
.83 
.31 

.88 
.86 
.42 
.58 


0.042 
.028 
.030 
.022 
.028 
.034 
.040 

.036 
.036 
.039 
.065 


3.07 
2.88 
2.58 
2.84 
2.89 
8.06 
2.88 

8.00 
3.00 
3.09 
3.40 


4.07 


July 27 


4.40 


Aug. 24 


4.44 


Sept. 21 


4-12 


Oct. 19 


4.26 


Nov. 16 


4.04 


Dec.14 


4.74 


1908. 
Jan. 11 


4.25 


Feb.8 


4.09 


Ifflr.7 


3.94 


Apr. 4 


4.50 







COW NO. 209. 



1907 
Aug. 17.... 

Sept. 14 

Oct. 12 

Nov. 9 

Dec. 7 

19Q8 

Jan. 4 

Feb. 1 

Feb. 29 

Mar. 28 

Apr. 25 

May 23 

June 22 

July4» 



1.0818 


88.76 


11.24 


8.12 


0.50 


0.39 


0.051 


3.12 


1.0305 


89.77 


10.23 


7.63 


.45 


.34 


.032 


2.60 


1.0300 


89.37 


10.63 


7.90 


.45 


.34 


.037 


2.74 


1.0299 


88.93 


11.07 


8.05 


.47 


.36 


.038 


8.24 


La297 


88.85 


1L15 


8.02 


.46 


.35 


.034 


8.14 


1.0303 


80.05 


10.06 


8.14 


.46 


.36 


.042 


2.81 


1.0305 


88.80 


11.20 


8.27 


.50 


.89 


.044 


2.94 


1.0306 


88.78 


11.23 


8.46 


.40 


.40 


.047 


8.01 


1.0313 


88.42 


11.58 


8.57 


.52 


.41 


.038 


3.01 


1.0325 


87.42 


12.58 


9.06 


.60 


.49 


.057 


3.62 


1.0344 


87.02 


12.99 


9.53 


.65 


.53 


.063 


3.46 


1.0348 


86.49 


13.51 


9.61 


.73 


.59 


.084 


3.90 


1.0822 


85.48 


14.52 


9.25 


.71 


.58 


.067 


5.28 



4.40 
4.00 
4.17 
3.95 
4.42 



4.36 
4.10 
3.94 
4.43 
4.62 
4.79 
4.15 
4.30 



COW NO. 300. 



1906, 

Jan. 25 

Feb. 22 

Mar. 21 

Apr. 18 

May 16 

June 13 

July 11 

Aug. 8 

Sept. 5 

Oct. 3 



1.0329 
1.0325 
1.0326 
1.0308 
1.0313 
1.0302 
1.0300 
1.0309 
1.0320 
1.0319 



86.93 
87.73 
87.86 
88.19 
88.35 
88.66 
88.62 
87.86 
87.44 
86.15 



13.07 
12.27 
12.14 
11.81 
11.66 
11.35 
11.38 
12.15 
12.56 
13.85 



9.06 
8.66 
8.76 
8.45 
8.34 
8.09 
8.07 
8.62 
8.82 
9.33 



0.53 
.47 
.48 
.47 
.46 
.47 
.46 
.49 
.57 
.67 



0.44 
.40 
.40 
.38 
.39 
.39 
.39 
.44 
.52 
.69 



0.039 
.031 
.027 
.030 
.031 
.029 
.029 
.019 
.017 
.032 



4.01 
3.61 
3.38 
3.86 
3.32 
3.26 
3.30 
8.53 
3.74 
4.52 



5.14 
4.81 
4.64 
4.87 
4.96 
4.57 
4.82 
5. OB 
5.13 
4.39 



t Last period, two weeks. 



BESULTS OF THE EXPEBIMEKTS. 



29 



Table 5. — Average analysis of the milk of each cow, by 4'Week periods — Continued. 

cow NO. 301. 



Foot weeks end- 
Ing- 


Spoclflc 
gravity 
of milk. 


Water. 


Total 
soUds. 


Solids 
not fat. 


Total, 
nitrogen. 


mtro^n. 


Albumin 
nitrogen. 


Fat 


Sugar. 


1007. 
Oct. 26 


1.0843 
1.0327 
1.0336 

1.0334 
1.0828 
1.0331 
1.0324 
1.0320 
1.0321 
1.0310 
1.0280 
1.0318 
1.0343 


Percent. 
86.80 
87.61 
87.43 

87.37 
86.01 
87.16 
87.37 
87.36 
87.61 
88.22 
86.46 
86.96 
86.43 


Percent. 
13.20 
13.60 
13.67 

13.64 
13.09 
13.86 
12.63 
12.64 
12.49 
11.78 
13.66 
18.04 
13.27 


Per cent. 
9.31 
8.76 
8.76 

8.83 
9.01 
9.06 
8.70 
8.70 
8.82 
8.21 
8.63 
9.08 
9.09 


Percent. 
0.66 
.50 
.48 

.61 
.61 
.63 
.61 
.60 
.63 
.53 
.63 
.57 
.66 


Percent. 
0.47 
.40 
.39 

.43 
.43 

.43 
.42 
.42 
.46 
.43 
.46 
.53 
.57 


Percent. 
a048 
.033 
.043 

.036 
.043 
.046 
.043 
.086 
.033 
.036 
.033 
.024 
.032 


Percent. 
3.87 
8.74 
3.81 

3.81 
4.06 
3.78 
3.05 
3.04 
3.67 
3.58 
4.02 
3.06 
4.18 


Percent. 
6.17 


Noy.33 


4.73 


Dec. 21 


6.68 


1908. 
Jan. 18 


6.16 


Feb. 16 


4.77 


Mnr.H 


4.43 


Apr. 11 


6.38 


11^9 


6.13 


Jnii^fl - 


4.86 


July 4 


4.88 


AlM.l 


4.80 


Auff. 30. 


5.04 


Sept. 10 


5.13 







COW NO. 400. 



1007. 

NOT.3 

Nov. 30 

Dec 38 

1906. 

Ian. 26. 

Feb. 22 

lfar.21 

Apr. 18 

llaylO 

Jane 13 

July 11 

Aag. 1 



• 

1.0356 


86.20 


i3.n 


0.60 


0.64 


0.46 


0.056 


4.13 


1.0333 


86.71 


13.20 


0.30 


.61 


.41 


.063 


4.09 


1.0333 


86.06 


13.06 


0.06 


.46 


.38 


.033 


o* vn 


1.0330 


87.52 


13.48 


8.84 


.48 


.38 


.043 


8.66 


1.0343 


86.04 


13.06 


0.37 


.63 


.44 


.045 


3.70 


1.0340 


86.06 


13.06 


0.36 


.54 


.44 


.043 


3.60 


1.0341 


87.04 


13.06 


0.11 


.66 


.46 


.067 


3.85 


1.0344 


86.02 


13.06 


0.35 


.66 


.46 


.046 


3.73 


1.0330 


86.07 


13.08 


8.96 


.58 


.46 


.046 


4.05 


1.0304 


87.67 


13.43 


8.38 


.60 


.48 


.038 


4.16 


1.0296 


87.16 


13.84 


8.67 


.60 


.53 


.087 


4.17 



6.40 
6.06 
6.44 



6.13 
4.87 
4.05 
5.06 
5.10 
4.65 
4.22 
4.26 



COW NO. 402. 



1907 
Nov. 16.... 
Dec. 14 

1006 

Jan. 11 

Fab.8 

lfar.7 

Apr.4 

idorS 

May 30 

June 27 

July 18 



1.0341 


86.27 


13.74 


. 0.10 


a53 


a44 


ao6i 


4.66 


1.0336 


86.71 


13.30 


0.13 


.58 


.43 


.040 


4.17 


1.0385 


86.03 


13.07 


0.10 


.61 


.43 


.047 


3.07 


1.0340 


86.04 


13.07 


0.37 


.54 


.44 


.046 


3.80 


1.0337 


86.87 


13.16 


0.33 


.65 


.46 


.045 


3.84 


1.0339 


87.03 


12.07 


0.06 


.66 


.44 


.045 


3.02 


1.0333 


86.06 


13.02 


0.04 


.66 


.46 


.042 


3.06 


1.0335 


87.07 


12.03 


0.04 


.67 


.46 


.042 


3.00 


1.0332 


86.20 


13.81 


0.14 


.63 


.53 


.056 


4.67 


1.0326 


86.06 


13.04 


0.68 


.70 


.60 


.020 


4.42 



4.77 
5.38 



5.09 
4.73 
4.65 

5.00 
&20 
4.73 
4.61 
4.31 



COW NO. 403. 



1008. 
Mar. 14 


1.0348 
1.0828 
1.0327 
1.0317 
1.0816 
1.0313 
1.0321 
1.0333 
1.0834 
1.0821 
1.0327 


87.16 
87.85 
88.26 
88.44 
88.44 
88.36 
87.23 
87.48 
87.62 
87.10 
86.81 


12.85 
12.16 
11.76 
11.66 
11.66 
11.66 
12.77 
13.68 
13.38 
13.00 
13.10 


0.37 
8.78 
8.57 
8.40 
8.43 
8.53 
0.64 
8.07 
8.64 
8.90 
0.16 


a52 
.40 
.47 
.47 
.40 
.61 
.53 
.67 
.58 
.60 
.64 


a42 

.38 
.36 

:i? 

.43 

.46 
.47 
.46 
.45 
.48 


0.053 
.061 
.043 
.044 
.046 
.033 
.030 
.046 
.067 
.003 
.002 


3.68 
3.38 
3.18 
3.16 
3.14 
3.13 
3.23 
3.65 
3.85 
4.00 
4.05 


6.21 


Apr. 11 


6i22 


MavO 


6.30 


June 6 


6.00 


July 4 


4.68 


Amr.1 


5.16 


Aug. 20. 


4.98 


8^25 


5.11 


Oct 24 


4.06 


Nov.31 


4.17 


Dec 10 


4.47 







30 



STAGE OP LACTATION AND PBOPERTIES OF MILK. 



Table 5. — Avenge analynsofthe milk o/eadi cow, hy 4-^eek periods — Continued. 

COW NO. 4. 



Four weeks ending— 


Ash.' 


RelfttlTe 

sixeof 

globules. 


Reictiert- 
Heiasl 

number. 


Todin 
number. 


Saponifi- 
cation 
number. 


Reib«o- 

tive in- 
dex. 


Melting 
point. 


1906. 
Dec. 22 


Percent. 


863 

423 
370 
229 
207 
236 
299 
818 
228 
107 


29.22 

28.72 
28.62 
28.50 
28.90 
29.20 
20.87 
28.83 
25.24 
26.96 


8L06 

28.04 
29.01 
29.94 
28.84 
28.03 
31.40 
29.75 
32.27 
32.16 


23L1 

283.1 
232.9 
229.1 
230.7 
229.0 
227.8 
229.4 
234.4 
235.9 


1.4601 

1.4505 

'*'i.'4604' 
1.4593 
1.4692 
1.4589 
1.4594 


82.30 


1907. 
Jan. 19 




32.63 


Feb .10 


33.39 


Mw. 16 


33.25 


Apr. 13 ' 


33.30 


Meyll.. 


33.44 


June 8 . r ' 


32.94 


JulyO ' 


33.24 


Aac. 3 


33.03 


Sept. 7* ! 


1.4684 


32.97 







COW NO. 99. 



1907. 
Feb. 2 




560 

339 
325 
274 
264 
349 
370 
307 
270 
200 
283 
815 


30.10 
28.88 
32.00 
80.06 
27.67 
81.21 
27.03 
27.34 
27.03 
25.83 
24.73 
18.43 


32.88 
29.46 
28.90 
26.76 
29.99 
27.29 
27.03 
27.37 
28.71 
28.80 
27.61 
29.55 


230.0 
232.1 
209.5 
232.3 
227.7 
231.7 
227.3 
230.8 
234.3 
231.4 
229.4 
219.0 


1.4601 
1.4507 
1.4502 
1.4580 


24.94 


Mar. 2 




33.24 


Mar. 30 




83.36 


Apr. 27 i 


34.53 


May2f>.. i 


83.78 


Jum22 1 


1.4590 


84.06 


July 20 

Aug. 17 

Sept. 14 

Oct. 12 


0.05 
.04 
.05 
.70 
.81 
.91 


34.07 


1.4580 


34.33 
34.64 


1.4558 
1.4564 
1.4567 


38.81 


Not. 9 


34.88 


Nov. 30 


34.86 







COW NO. 118. 



1906. 
Nov. 3 






29.64 
23.28 
24.14 

• 23.60 
28.90 
24.04 
26.66 
28.12 
26.04 
22.86 
22.79 
20.22 
14.23 
14.21 


30.31 
30.33 
32.54 

28.09 
31.55 
30.43 
28.67 
32.49 
33.67 
81.43 
81.14 
82.47 
88.48 
86.82 


228.6 
224.7 
220.6 

229.0 
230.2 
226.6 
229.4 
234.8 
225.1 
227.6 
237.0 
223.9 
219.5 
219.1 




26.63 


Dec 1 








82.66 


Deo. 29 




417 

879 
858 
873 
301 
834 
836 
2S0 
842 
220 
438 
461 


1.4604 

1.4602 
1.4600 
1.4696 
1.4596 
1.4602 
1.4601 


83.81 


1907. 
Jan. 26 . , 




33.31 


Feb. 23 




83.80 


Mar. 23 




33.40 


Apr. 20 




33.92 


May 18. 




33.66 


JnviA IB -•- - 




33.89 


July 13 


0.64 
.09 
.76 
.85 


83.59 


Auk. 10 


1.4578 
1.4502 
1.4570 
1.4579 


33.81 


Sept. 7 


33.88 


Oct. 5 


33.46 


Oct.26> 


33.60 









COW NO. 205. 



1907. 
Aug. 17 


ae4 

.61 
.64 
.60 
.09 

.66 
.59 
.63 
.62 
.02 
.03 
.66 


242 
147 
148 
147 
127 

82 

107 

96 

98 

90 

81 

117 

102 

179 


26.66 
26.01 
26.33 
27.38 
27.82 

26.92 
28.05 
27.53 
27.86 
26.06 
25.63 
20.89 
12,77 
10.27 


37.12 
34.54 
83.23 
81.85 
81.77 

32.64 
32.62 
33.45 
34.07 
35.55 
35.40 
37.53 
42.57 
42.24 


242.2 
229.3 
229.0 
232.0 
230.8 

228.7 
228.1 
227.0 
225.0 
223.9 
226.3 
220.8 
210.1 
205.9 


1.4596 


^41 


Sent. 14 


32.67 


Oct. 12 


1.4559 


33.39 


Nov. 9 


33.76 


Dec. 7 


1.4568 

1.4571 
1.4564 
1.4566 


33.00 


1006. 
Jan. 4 


32.03 


Feb. 1 


32.88 


Feb. 29 


32.98 


Mar. 28 


33.26 


Aor. 25 


33.09 


Mav23 




33.01 


June 20 




32.54 


July 18 




41.80 


Auc.8 


. .70 




48.34 









1 Ash not determined for cow No. 4. 



s Last period, 6 weeks. 



BESULTS OF THE EXPEBIMEKTS. 



31 



Tablb 5. — Average analysis of the milk of each oowj by i-toeeh periods — Continued. 

cow NO. 206. 



Four weeks ending- 



June 29. 
July 27. 
Aug. 24. 
Sept. 21 
Oct. 19. 
Not. 16. 
Dec. 14. 



Jan. 11. 
Feb. 8. 
lfar.7. 

AlKT. 4. 



1907. 



1908. 



Aah. 



PercetU, 



a62 
.64 
.71 
.66 



.67 



.67 
.67 
.83 
.86 



Relative 

size of 

lobules. 



263 
269 
124 
167 
184 
156 
132 



110 

96 
74 
79 



Relchert- 

Meissl 

number. 



30.15 
29.48 
28.15 
24.68 
27.19 
24.51 
24.28 



28.30 
23.53 
».76 
17.62 



lodln 
number. 



31.00 
30.57 
35.53 
31.70 
31.79 
81.67 
33.14 



34.26 
33.91 
35.27 
36.53 



Saponin- 

cation 

number. 



230.7 
228.3 
242.4 
233.7 
232.4 
231.2 
229.7 



225.6 
224.4 
219.9 
216.4 



Ketrao- 
tive in- 
dex. 



1.4584 
1.4559 
1.45G5 



1.4569 



1.4576 
1.4573 
1.4575 



Melting 
point. 



a 



32.95 
33.62 
31.94 
32.06 
32.47 
32.47 
32.64 



33.13 
32.81 
32.92 
38.80 



COW No. 200. 



1907. 

Aug. 17 

Senpt. 14 

Oct. 12 

Nov.9 

Dec? 

1906. 

Jtfl.4 

Feb.l 

FlBb.29 

lfar.28 

Apr.26 

May 28 

June 22 

July4i ,.... 



0.72 
.69 
.66 
.71 
.75 



.64 
.67 
.70 
.71 
.74 
.66 
.68 
.76 



821 

139 
136 
138 
104 



80 
98 
99 

106 
79 
63 
76 

118 



25.65 
26.84 
25.10 
27.05 
24.82 



24.68 
22.79 
23.47 
24.23 
20.17 
21.32 
20.70 
21.14 



89.46 
83.32 
32.89 
33.10 
33.53 



34.91 
36.62 
35.50 
37.01 
39.06 
35.35 
36.60 
89.03 



237.2 
230.6 
231.6 
230.8 
228.3 



229.0 
224.0 
222.4 
222.0 
219.2 
222.0 
220.3 
215.3 



1.4598 



1.4565 
'i.'4676 



1.4578 
1.4574 
1.4570 



32.58 
32.16 
32.06 
31.84 
33.04 



31.60 
32.30 
32.78 
32.85 
33.82 
33.15 
35.45 
37.39 



COW No. 300. 



An. 25. 
Feb. 22. 
Mar. 21. 
Apr. 18. 
lUylO. 
Jane 13. 
Jnly 11. 
Aag.8. 
firat.5. 

oa.8.. 



1906. 



0.66 
.67 
.67 
.68 
.66 
.62 
.68 
.61 
.57 



235 

168 

148 

135 

115 

133 

93 

80 

75 

128 



27.66 
28.96 
27.76 
26.76 
26.83 
25.76 
24.57 
23.87 
23.09 
17.96 



32.68 
28.70 
27.60 
31.91 
27.60 
29.61 
35.30 
37.32 
35.23 
37.74 



232.6 
230.7 
232.3 
224.8 
229.2 
230.1 
224.5 
222.0 
223.9 
217.2 



1.4569 
1.4554 



COW NO. 301. 



34.80 
33.30 
33.45 
33.54 
33.74 
33.87 
33.83 
33.30 
33.30 
34.04 



Oct. 26... 
Nor. 23.. 
]>ee.21.. 



Jan. 18.. 
Feb. 15. 
Mar. 14. 
Apr. 11. 
May9.. 
JmieO.. 
July 4.. 
Aug. 1. . 
Aug. 29. 
Sept. 19. 



1907. 



1908.' 



0.64 
.66 
.67 



.59 
.60 
.64 
.62 
.55 



.60 
.51 
.55 
.70 



282 
189 
142 



156 
165 
178 
163 
151 
146 
114 
146 
93 

no 



30.50 
27.09 
26.58 



25.13 
24.88 
26.79 
25.59 
26.40 
24.42 
24.36 
18.09 
21. ?2 
20.67 



28.58 
29.91 
30.56 



29.85 
30.93 
30.31 
31.04 
30.54 
32.64 
3.'i.n 
44.11 
39. G2 
36.80 



236.9 
234.1 
232.0 



230.4 
227.5 
229.7 
219.6 
228.3 
228.4 
224.3 
216.2 
218.7 
221.3 



1.4564 
1.4567 
1.4560 



1.4563 
1.4563 



32.07 
33.21 
32.61 



32.80 
33.85 
32.98 
33.96 
33.55 
33.33 
33.10 
34.35 
33.23 
33.28 



32 



STAGE OP LACTATION AND PBOPBRTIES OF MILK. 



Tablb 5. — Avtrage analyns of the mUkofetKh cow, by 4^week periodt — Ck>iitinaed. 

cow NO. 400. 



Four weeks ending— 


Aah. 


B^tive 

slseof 

{Lobules. 


Reldiert- 

Meissl 

number. 


lodln 
number. 


Saponill- 

cation 

number. 


Refirao- 

ttveln. 

dez. 


Melting 
point. 


1907. 
Nov. 2 


PtT cent. 

0.70 

.72 

.69 

.67 
.67 
.75 
.72 
.70 


442 
503 
317 

245 
250 
277 
231 
197 
214 
179 
194 


80.77 
20.31 
25.05 

25.90 
28.68 
26.54 
24.70 
25.99 
24.46 
22.57 
22.25 


30.13 
32.12 
39.05 

31.36 
31.66 
33.31 
35.71 
33.25 
34.28 
36.91 
38.49 


232.3 
231.7 
224.2 

230.0 
229.4 
227.2 
223.9 
226.5 
224.9 
220.5 
216.8 




•c. 

33.91 


Nov. 30 


L4570 
1.4581 

1.4563 
L4557 


82.99 


Dec. 28 


81.61 


1908. 
Jan. 25 


33.15 


Feb. 2? 


83.01 


Mar. 21 


83.88 


Apr. 18 

May 16 

June 13 




83.63 




34.13 




84.21 


July 11 


.70 
.86 




86.40 


Au«.l ; 




36.49 









COW NO. 402. 



1907. 

Nov.16 

Dec.l4 

1908. 

Jan. 11 

Feb.8 

Mar.7 

Apr. 4 

May2 

May 30 

June 27 

July 18 



aTi 

.73 

.70 
.71 
.73 
.73 
.74 
.73 
.60 
.86 


566 
561 

394 
374 
380 
232 
271 
214 
213 
198 


30.72 
37.14 

26.69 
26.60 
26.07 
24.12 
23.75 
23.93 
18.39 
16.61 


30.76 
29.21 

31.15 
30.42 
32.08 
85.16 
35.13 
35.47 
41.01 
42.19 


234.3 
233.9 

239.8 
223.0 
228.3 
234.3 
223.7 
222.7 
215.8 
211.5 




L4566 

L4560 
1.4560 













32.60 
82.70 



33.20 
83.00 
32.05 
83.09 
33.76 
33.70 
84.65 
36.31 



COW NO. 403. 



1906. 
Ma'. 14. 




357 
803 
213 
183 
134 
141 
146 
147 
203 
175 
128 


29.36 
36.67 
36.31 
36.30 
25.60 
26.02 
26.38 
24.63 
23.27 
24.25 
25.51 


33.33 
35.18 
33.10 
33.76 
35.28 
35.57 
34.96 
36.34 
37.32 
35.24 
35.04 


234.3 
225.4 
228.1 
220.9 
226.4 
230.1 
224.6 
225.1 
223.8 
236.4 
226.6 




83.70 


Anr. 11 


a67 
.71 
.66 
.61 
.57 
.69 
.69 
.69 
.76 
.87 




83.33 


May 9 




32.70 


Juji« 6 . . 




33.60 


July4 




33.15 


Aug. 1 




33.98 


Aujz. 20 




33.54 


Sept. 26 




83.65 


Oct. 24 




33.14 


Nov. 21 




33.28 


Dec. 19: 




32.83 









TOTAL NITROGEN AND PROTEIN. 

Table 6 gives the average per cent of total nitrogen in the milk 
of each of the 11 cows by 4-week periods. The figures for the in- 
dividuals are also grouped by breeds in order that an average may 
be given representing each breed, and a grand average including all. 
The averages are also expressed in per cent of protein (Nx6.38). 
The changes in the total protein for each cow by 4-week periods is 
represented in figures 1 to 11; and average for the 11 animals in 
figure 12. 



BB8ULTS 07 THE EXPBBIMEKTS. 



33 



"fi^JffODS 




JO 









300 



Fto. l.~Diagnm showing variation in yield and composition of milk of oow No. 4 at end of each 4-week 

period. 




Vto. 2d— Diagmm diowing variation In yield and eomposltion of nUDc of oow No. W at end of eadi 4-week 

period. 

58223*'— BuU. 156—18 3 



34 



STAGE OF LAOTAXIOl} AND PB0PEBTIE8 OF MILK. 




Fio. 3.— Diagnin showing TBriatioo in yield and composition of milk of oow No. 118 at end of each i-mek 

period. 




Ffo. 4.~Diagiam showing variation in yMA and composition of milk of oow No. 306 at end of saoh 

period. 



BESULTS OF THE EXPERIMENTS. 



35 



—A^^/i^/OOS- 




Itok 5.— Dlagiain sbowliig variation in yield and oompodtion of milk of oow No. 206 at end of each 4-week 

period. 



36 



STAGE OF LACTATION AND PBOPEBTIES OF MILK. 




Fio. 6.— Diagram showing yarlaUoo in yield and oompocitioQ of milk of oow No. aoo at end of eadi 4-wedc 

period. 



BESULTS OF THE EXPEBIMEKI8. 



37 




Fio. 7.— DiBgcam showing yariatioa in yield and oomposltioD of mUk of oow No. 300 at end of eaoh 4-week 

period. 




VIO. &— Diagram sbowing yariation in yield and composition of mfflc of oow No. 301 at end of each 4-week 

period. 



88 



STAGE OF LACTATION AND PBOPSBTIES OF KILK. 




Via. 9«— DJagnin Bhowing vwiatkm In jrleld and oomposltiaii of milk of oow No. 400 at end of each 

period. 




Fio. 10.— Diagram showing variation In yield and oomposltloii of mUk of oow No. 408 at end of each 4-w6ek 

period. 



BBSULTS OF IHB EZPEBIMENTS. 



39 




Fio. U.— Diagram showlog variation in yield and oompofiltiofi of milk of cow No. 408 at end of each 4-week 

period. 



M 



■ T 



^ — f 



/9 



y/ 



/r 



Si 



•♦♦• 



"♦♦- 






9frA<x^ 




■7 



TlOTS^Ji SQL/iX3it ^l^gmfs^ % /£. 7^ 



FU. 12.— Diagram showing variation in yield and composition of milk at end of each 4-week period; 

average for 11 cows. 

It is a well-established fact that the milk secreted immediately 
after parturition is abnormally high in albumin. But it is not 
generally understood that this is also true, although in lesser measure, 
of the other milk proteids, and that the normal per cent of this 
constituent is not reached for several weeks. The change in total 
nitrogen during the first 6 weeks is shown in Table 7. It must be 
borne in mind in studying this table that all analyses are made from 



40 



STAGE OF LACTATIOK AND PB0PEBTIE8 OF MILK. 



what would be generally considered normal milk. In no case were 
the samples taken until the colostrum period was passed; therefore 
we can not ascribe the high total nitrogen content during the first 
few weeks to the high albumin content of the colostrum. It will be 
noted that in every case but one the per cent of nitrogen starts high, 
drops decidedly the second week; and reaches the lowest point in 
from 4 to 6 weeks. 

After the lowest point is reached the per cent of total nitrogen 
remains fairly constant until about the eighth month of the lactation 
period, when it begins to rise gradually. Toward the end of the 
period it rises more rapidly until it attains its maximum at the end 
of the lactation period. Ilie range of variation with individual cows 
and with the average is shown below. 



MftTrintnm range In per oent of total protein 
Iflnlmnm range in per oent of total protein. 
Average (11 oowB) , 



Low. 



3.36 
3.83 
3.»7 



Average. 



3.68 
3.70 
8.30 



High. 



4.68 
4.31 
4.31 



If we express the average total protein by 100 per cent the varia- 
tion will be as follows: 



ICaximom range. . 
Minimum range.. 
Average (11 cows) 



I4OW. 



88.0 
89.7 
90.0 



Avenge. 



100 
100 
100 



Hic^ 



169.0 
113.7 
130.0 



Total range 

in per oent 

of average 

protein. 



81.0 
34.0 
4a6 



The data show a wide range of variation in total protein during 
the normal lactation period. As compared with the fat, generally 
assumed to be the most valuable constituent, it will be found with 
the 11 cows used in this investigation that the variation in total 
protein exceeds the variation in fat. This is shown in figure 12. 
However, if the composition of the milk of each separate milking 
was known it is quite certain from other data at hand that the range 
of variation in the per cent of fat would be much greater than with 
thecasein; that is to say, the fat varies more from milking to milking 
than does the total nitrogen; but eliminating these temporary varia- 
tions the per cent of fat is less affected by the period of lactation 
than is the total nitrogen. 

It might be mentioned at this point that the last samples included 
were stiU what would be considered as normal milk. In some in- 
stances analyses were made on samples taken up to the time that 
the cows ceased to produce milk, but these results are not included 
in the tables. 



BBSULTS OF THE EXPERIMENTS. 



41 



Tablb 6. — Average total nitrogen for each eow and average total nitrogen and protein for 

each breed, by 4-y>eek periods. 



Cow No. 



4... 
99.. 
118. 



Ayense tolal nl^ogen for 
JeneyB 

Averago total protein for 
Jonoys 



206. 
a09. 



Avwage total 'nitrogen for 
Holsteins 

Awage total protein for 
Holsteins 



»0 

A^cnn total nitrogen for 
AynhirSB... 

Avenge total protein for 
Ayrsnires 



400. 
402. 
403. 



Average total nitrogen for 
Sborthoms 

Average total protein for 
fihortbonis 



GiBod avenge total nitrogen. 

Qrand avenge total protein . 

VarJaUon In percentage of 
total protein, on basis of 
Itast pertod l)eing 100 per 
cent 



a 52 
.61 



.52 
3.32 



.40 
.44 
.50 



.48 
8.06 



.53 
.56 



.55 
3.51 



.54 
.53 
.52 



.53 
8.38 



.51 
a25 



PjcL 

a53 

.51 

.51 



.52 
8.32 



.43 
.88 
.45 



.42 
2.68 



.47 
.50 



.49 

ai8 



.51 
.52 
.49 



.51 
3.25 



.48 
3.06 



100 94 



PxL 

as? 

.51 
.56 



65 

a 51 



.44 
.37 
.45 



.42 
2.68 



.48 
.48 



.48 
3.06 



.46 
.51 
.47 



.48 
3.06 



.48 
3.06 



94 



5 

o 



Pxt 

a 61 

.40 
.54 



.55 
3.51 



.44 
.39 
.47 



.43 

2.74 



.47 
.61 



.49 
3.13 



.48 
.54 
.47 



.50 
3.19 



.49 

ai3 



96 



PxL 

aeoi 

.49 
.65 



.58 
3.70 



.45 
.42 
.45 



.44 

2.81 



.46 
.61 



.49 

ai3 



.53 
.55 
.49 



.52 
3.32 



.51 
3.25 



100 



CQ 



PxA. 

a 69 

.49 
.65 



.68 
3.70 



.45 
.42 
.46 



.44 
2.81 



.47 
.53 



.50 
3.19 



.54 
.65 
.51 



.53 
3.38 



.61 
8.25 



100 



3 



P.ct 

a50 

.481 
.67 



.58 
8.70 



.45 
.41 
.50 



.46 

2.87 



.46 
.51 



.49 
3.13 



.56 
.56 
.63 



.55 
a 51 



.52 
3.32 



102 



I 

I 



PM. 

a 57 

.501 
.64 



.67 
3.64 



.44 
.43 

.49 



.45 
2.87 



.48 
.60 



.60 

3.19 

"756 
.57 
.57 



.57 
3.64 



.52 
a32 



102 



6 
B 



P.rt. 

a62 
.62 
.64 



.60 
3.76 



.48 
.44 
.62 



.48 
3.06 



.67 
.63 



.56 
3.51 

Tsi 

.63 
.58 



.60 

I 

3.83 



.56 
3.57 



110 



I 



P.ct. 
a66 

.56 
.64 



.62 
8.06 



• 4o 

.61 

.601 



.63 
3.38 



.67 
.63 



.60 
3.83 

"Too 

.70 
.60 



402 



.60 
3.83 



118 






P.eL 



a62 

.65 



.64 
4.08 



.51 
.71 
.65 



.62 
3.96 



.53 



69 



64 



.62 
3.96 



.61 
3.89 



120 



P.ct 



0.66 
.70 



.68 
4.34 



56 



.73 



.64 
4.08 



.57 



.64 
4.08 



125 



P-Ct 



a 75 



. Uv 



.71 



.65 
416 



.65 



.68 
4 34 



133 



i 



I 



P.«t 



a77 



.65 



.64 



Tablb 7. — Showing change in the total nitrogen of each cow during the first 6 weeks. 



Week. 


Cow 


Cow 


Cow 


Cow 


Cow 


Cow 


Cow 


Cow 


Cow 


Cow 


No. 4 


No. 99. 


No. 206. 


No. 206. 


No. 209. 


No.30a 


N0.80L 


No.40a 


No. 402. 


No. 408. 




PereL 


PereL 


PereL 


PercL 


PereL 


PereL 


PereL 


PereL 


PercL 


PereL 


1 


a63 


a66 


a54 


a6S 


a 61 


a61 


a64 


a67 


a58 


a67 


2 


.52 


.52 


.51 


.48 


.49 


.63 


.67 


.64 


.61 


.61 


8 




.51 


.46 


.40 


.44 


.50 


.64 


.63 


.61 


.51 


4 




.46 


.46 


.39 


.45 


.48 


.60 


.63 


.52 


.60 


5 


.67 


.51 


.44 


.37 


.45 


.46 


.49 


.61 


.50 


.61 


6 


.40 


.52 


.43 


.38 


.43 


.46 


.50 


.52 


.62 


.48 



It is believed this change in the per cent of total nitrogen during 
the lactation period, as shown by the data giyen, is entirely normal. 
Every cow, with one exception, showed a decline during the first 
few weeks, and all showed a rise in the latter end of the period, 
although with some this was much more marked than with others. 



42 STAGE OF LACTATION AND PBOPEBTIBS OF MILK. 

The authors surest that this normal decline in total protein m 
the early part of the lactation period is due to the physical condition 
of the animal. Under normal conditions a cow is in a good physical 
condition at calying time. That is to say, she has been on a high 
plane of nutrition and has stored surplus fat and protein in the body. 
This is a provision of nature to prepare the animal to produce milk 
for her young, if necessary partly at the expense of her own body. 

After calving, imder normal conditions, the cow loses in weight 
for from 2 to 10 weeks. This means that she does not consume 
sufficient food to furnish maintenance and support the milk pro- 
duction. Consequently, she draws for some time on her stored 
nutrients and loses weight. This loss of weight happened with the 
11 cows used in the investigation here reported. Peifaaps on the 
average the decline in weight was rather more than the normaL 
Unfortunately, no complete records of weight were kept. 

However, by referring to Tables 27 and 28 data may be studied 
that bear directly upon this problem. The 5 cows dealt with in 
these tables were used in another investigation in which it was an 
important part of the plan to maintain a uniform weight throughout 
the milking period. The weights given are the averages of daily 
weight for the period included. It will be observed that except in 
the case of No. 27 practically uniform weights were maintained. 
No. 27, on accoimt of the lai^e amoimt of milk produced and because 
she suffered from some indigestion, lost weight rapidly during the 
first 10 days. The total nitrogen in her milk was also low at this 
stage and, in fact, follows her decrease and increase in weight in 
general throughout the milking period. The other 4 cows were 
maintained at practically the same weight throughout the entire 
milking period, and it will be observed that the per cent of total 
nitrogen is almost constant. It should be understood that these 
cows were farrow, which may account for the fact that there was no 
marked increase in the total nitrogen in the last part of the lactation 
period, but it does not account for the fact that there was no decline 
in the first few weeks. 

OASEIN KrrBOOEK AND CASEIN. 

Table 8 gives the casein nitrogen by 4-week periods for each cow, 
with an average for each breed and for the 1 1 cows. The averages 
are also expressed in casein found by using the factor 6.38. 

The variations in the casein nitrogen during the lactation period 
are similar to those of the total nitrogen. There is the same decline 
during the first few weeks, followed by a gradual rise lasting from 
5 to 8 months, then a more rapid increase to the end of the period. 



BESX7LTS OF THE EXPEBIMENTS. 



43 



The range of variations in caseia content with individual cows and 
with the average is shown below: 



ICaximimi iBage In per cent casein 
Minimom mge in per cent ossein. 
(llOOWB) 



Low. 



2.04 
2.30 
2.32 



Avenge. 



3.14 
2.61 
2.68 



Hic^. 



3.89 
3.06 
3. £6 



If we express the average casein content by lOO per cent, the maxi- 
mum and minimum would be as follows: 



• 
• 


Low. 


Average. 


High. 


Total range 

in per cent 

of avenge 

casein. 




64.0 
88.1 
86.6 


100 
100 
100 


123.8 
117.2 
130.0 


58.9 


innfmnm nnin 


29.0 


Aywyn (11 oowb) 


45.5 







The maximum range of variation is 1.85 per cent of casein, or 58.9 
per cent of the average casein content; the minimum is 29.1 per cent 
of the average; while the 11 cows show an average variation of 1.21 
per cent, or 45.5 of the average casein content. It will be noted that 
the maximum range is caused by one exceptionally low figure, while 
the high point reached by the same animal is closer to her average 
than is the case with the average figures for the 11 cows. 

It wiU be further noted that with the average figures the minimtim 
figure is only 0.36 per cent below the mean, while the maximum is 
0.88 above. The greater variation in the latter is due to the exceed- 
ingly high figures reached at the end of the lactation period. 



44 



STAGE OF LACTATION AND PB0PEBTIB8 OF BULK. 



Tablb 8. — Average catdn 'nitrogen foit eack eow, and breed average, and average coMein 

nitrogen and caaeinfor eadi breed, by 4-M)eek periods. 



Cow No. 



4... 

90.. 
118. 



Avenge caeeln nltiogBn for 
AYera^B caaetn for Jeraeys. . . 

208 



Average cesetn nUiogeii for 

Hoistelns 

Avenge casein for Hobtetns . 



aoo. 

301. 
A 



verage caaeln nitrogan for 

Ayishires 

Avengecaeetn for Ayiabires . 



400. 
402. 
403. 



Average oaaetn nitrogen for 
Shoithams 

Average casein for Bhort- 
homs f 



Grand avenge casein nltro- 
Oiand avenge casein. 



uiana avenge casern 

Variation in jperoeatagB of 
casein on oasia of first 
period being 100 per cent. . 



P.O. 

a44| 

.42 



.43 
2.74 



.40 
.34 
.39 



.38 
2.42 



.44 

.47 



.46 
2.98 



.45 
.44 

.42 



.441 
2.81 



.42 
2.68 



ioa| 



P. a. 

0.38 
.41 

.321 



.87 
2.36 



.35 
.30 
.34 



.83 
2.11 



.40 
.40 



.40 
2.56 



.41 
.43 
.38 



.41 
2.62 



.37 
2.30 



P.rt 
0.48 
.40 
.48 



.46 
2.87 



.34 
.29 
.34 



.32 
2.04 



.40 
.89 



.40 
2.55 



.38 
.42 
.36 



.39 
2.49 



.89 
2.49 



98 



P.d. 
a 49 

.40 
.42 



.441 
2.81 



.36 
.30 
.36 



. 94 

2.17 



.38 
.43 



.41 
2.621 



P.CL 
0.48 
.40 
.54 



.47 

3.00 



.37 
.32 
.35 



.86 
2.23 



.39 
.48 



.41 
2.621 



.38 
.44 

.87 



.40 
2.56 



.39 
2.49 



98 



.44 

.45 
.87 



2.68 



.41 
2.62 



96 



P.e*. 

0.47 

.40 

.52 



.47 
3.00 



.38 
.83 
.86 



P.«t 

a47 

.89 

.64 



.47 
3.00 



.37 
.31 



.86 .86 
2.80 2.30 



.39 
.43 



.41 
2.62 



,44 
.44 

.48 



.441 
2.81 



.42 
2.68 



.39 
.42 



.41 
2.631 



.46 

.45 
.46 



.45 
2.87 



.42 

2.68 



100 100 






P.€<, 

0.46 
.54 



.47 
8.00 



,37 
.83 
.40 



.87 
2.86 



.44 

.42 



.48 
2.74 



.46 
.45 

.47 



.46 
2.93 



.43 
2.74 



102 






P.rt. 

0.50 

.42 

.a 



.48 
8.06 



.36 
.41 



2.42 



.62 
.45 



.49 
8.18 



.46 
.58 
.46 



.48 
8.06 



.45 
2.87 



107 



I 



P.et 

0.621 

.40 

.60 



P.tf. 



.51 



.49 .61 
8.18 8.2$ 



,39 
,42 
.49 



.48 

2.74 



.59 
.48 



.61 
8.26 



.48 
.56 
.45 



.50 
8.19 



.48 
3.06 



114 



P.efc 



0.68 
.66 



.54 

8.46 



.45 



.48 
.56 
.69 .69 



.61 
8.26 



.46 .62 



,58 



,48 



.61 
8.25 



.60 
8.19 



119 



3.82 



.68 
3.88 



126 



P.tL 



aoi 



.61 



8.61 



.67 



.87 
3.64 



186 



P.rt. 



a68 



.67 



.68 
8.70 



188 



Table 9 gives the ratio of casein nitrogen to total nitrogen for 
each animal. A striking uniformity will be observed in this table. 
From 79 to 83 per cent of the total nitrogen consists of casein in 
most cases. This ratio shows but little change even when the total 
protein makes a wide variation. 

Table 10 shows this relation by weeks for the first 5 and the last 
5 weeks of the lactation period. The milk at these two extremes of 
the milking period shows the widest variation in composition, but 
it will be noted the ratio between the total nitrogen and the casein 
remains practically unaffected. For example, cow No. 206 in the 
third period averaged 0.29 per cent total nitrogen, of which 78 per 
cent was casein. In her eleventh period she averaged 0.58 per cent 
total nitrogen, or exactly double that of the third period, of which 
82 per cent was casein. There seems to be only a slight effect that 
can be attributed to the advance in the period of lactation, and that 
is a small increase in the relative amount of casein in the last part of 



EBSULTS OF TSB BXPBBIMBNTS. 



45 



the lactation period^ whan the per cent of total protein increases 
veory rapidly. 

Tablb 9.—Averaff€ ratio ofeoiein nitrogen to total nitrogen^ by 4^W€ek periodB. 



Cow No. 



4 

99 

AveregB for Jcnoys , 

206 

Average tor Holsteiitt 

300 

ATera^B for AyrsbJies.. . . 

400 

402 

408 

ATttBge for ShoffhoRis. . . 

Onmd total avenge 



s 



Pad. 

0.85 
.82 



.77 



i 

OQ 



P.O. 
0.72 
.80 
.63 



.84 .72 



•82 .81 



.79 



.78 .76 



.79 .79 



.83 
.84 



.84 



.85 
.80 



.83 
.83 
.81 



.82 
T«3 



.80 
,83 

.78 



.80 

J8 



P.eL 
0.84 

.78 
.86 



.83 



.77 

.781 
.76 



.77 



.83 
.81 



.82 



.83 
.82 
.77 



.81 



P.et. 

0.80 

.82 

.78 



.80 



.82 
.77 
.71 



.79 



.81 

.84 



.79 
.82 
.79 



,80 



80 .80 



I 



P.cL 

0.80 

.82 

.83 



82 .81 



.82 
.76 
.78 



.79 



.85 
.84 



.85 

.82 
.76 



.81 



CQ 



P.ei. 

0.81 
.82 
.80 



.84 
.79 
.78 



.80 



.83 
.81 



.82 

.82 

.80 
.84 



80 .82 



.81 



J 



P.ct. 

0.8(^ 
.81 
.81 



.81 



.82 

.76 
.78 



,85 
,82 



i 



P.d. 

asi 



t 

I 



P.eL 

0.81 
.801 .81 
.84 .801 



.82 .81 .80 



.84 
.77 
.82 



P.cL 

a79 

.82 

.78 



.79 
.82 
.79 



.79 .81 



.80 



.90 
.84 



.84 .87 



.80 
.82 
.87 



.83 



.81 



.82 

.79 
.88 



.81 



.91 

.85 



.88 

li 
.84 
.79 



.80 



•1 



.82 



.81 
.82 
.82 



.82 



.88 
.81 



.85 

.80 
.80 
.75 



.78 



.81 



s 



PM. 



a82 

.79 



.81 



.84 
.82 
.82 



.83 



.87 



.87 



.75 



.83 



15 



P.cL 



0.80 
.79 



P.rt. 



0.81 



.80 .81 



.82 .86 



.81 



.82 



.82 



.91 



.91 



.84 



.88 



.60 



.84 



S 



P.ct. 



0.76 



.75 



.88 



.82 



Tablb 10. — Ratio ofcauin nitrogen to total mtrogenfor each oonojor fint S arid last 5 

weeks of lactation period. 



stage. 








Cow No. 


— 










4 


99 


118 


206 


206 


209 


300 


801 


400 


402 


408 


FIntweek 


0.88 

.79 
.80 

.76 
.78 
.79 


0.78 
.85 
.78 
.91 
.80 

.76 
.83 
.83 

.78 
.79 


a79 
.78 
.81 
.71 
.75 


0.80 
.80 
.83 
.80 
.80 

.82 
.89 
.90 
.89 
.85 


0.77 
.79 
.78 
.77 
.81 

.79 
.80 
.79 
.85 
.79 


0.76 
.80 
.77 
.80 
.76 

.79 
.86 
.78 
.84 
.79 


0.80 
.83 
.86 
.83 
.87 

.91 
.90 
.89 

.86 
.86 


a83 

.86 
.85 
.82 

.84 

.96 
.90 
.92 

.85 
.87 


0.82 
.83 
.85 
.79 
.80 

.82 

.84 
.90 
.86 
.93 


0.83 
.84 
.82 
.88 

.84 

.81 
.86 
.59 
.89 
.92 


0.81 


Seoondweek 

Third week. 

Foortfa wedc 

Fifth week 

Fifth week from end 


.84 
.76 
.76 
.72 

.78 


Fourth week 3ram end 


.76 


Third week from end 

'Seoond week firam end 

LMtweek.. x. 


.78 

.74 
.77 







ALBUMIN. 

Table 11 shows the amount of nitrogen as albumin. The average 
for the breeds and the grand average is also expressed as albumin by 
using the factor 6.38. The nitrogen as albumin was determined as 
already stated by the provisional method of coagulating the filtrate 
from the casdn-nitrogen determination by heat and finding the 
amount of nitrogen in the residue by the Gunning method. This 
method has proved unsatisfactory^ failing to yield concordant results 



46 



STAGE OF LACTATIOK AlH) FB0PEBTIE8 OF MILK. 



even when the greatest of caie is used in canying it out. This is no 
doubt due to the similarity of the albumin and the remaining soluble 
proteins. It is impossible with the provisional method to separate the 
albumin from the remaining protein with any degree of accuracy. 
This probabty accounts for some of the extreme yariations found in 
the results here reported. 

Table 11.— Average albumin niirogm and aUnmUn, by 4^W€ek periodt. 



Cow No. 



4... 
99.. 
118. 



Averwe albumin nitrogen 

for Joneyv.. 

Avenge aloaxnJn for Jeneys. 

906 

tfl^va •■••■ •••• •«••••«•••«••■•« 

AverMe albumhi nltfogen 

forHolstelns 

Average albumin for Hoi- 



aoo. 

801. 



Average albumin nitrogen 
for A yrahiree 

Average albumin for Ayr- 
shires 



400. 
403. 
403. 



Averue albumin nltngen 
for Shortlioma. 

Average albumin for Short- 
horns 

Gnad average albumin 
nitrogen. 

Grand average albumin 

Variation in peroentage of 
albumin, on basis of first 
period being 100 per oant. . 




Smce the figures given in Table 11 are in each case the average of 
4 samples each representing one week, the extreme variations which 
occur in the weekly tables given in the appendix and which it is 
recognized are due in part to the method used, are largely removed, 
and it is possible to study the general effect of the lactation period 
on the albumin nitn^en. 

The albumin nitrogen follows the same course as the casein nitrogen 
during the lactation period. In the beginning it is higher than the 
average, soon declines, reaching the minimum about the third month. 



BBSXTLTS OF THE EXFEBIMEKTS. 



47 



From this point on there is a gradual rise, which becomes much more 
pronounced at the end. The range in albumin by individual animals' 
in 4-week periods is as foUows: 



Low. 



ifityinn ini rangB In per cent albmniii ^ 

Mmimnm range in per cent albumin 

(UOOWB) 



0.191 
.169 
.181 



asio 

.218 
.279 



a608 



If we express the average albumin by 100, the results given above 
would be as follows : 





Low. 


A^eragB. 


TT%hr 


Total raofl 

in per cent 

ATeraoB 

albamm. 


ifurfflimm nnfle. 


61.6 
74.6 
64.8 


100 
100 
100 


19l!2 
123.0 
146. 1 


uao 




48.4 


Aybtba raunYll oowb) 


80L8 







Table 12 shows the ratio of albumin to total nitrogen. It will be 
observed that, like the casein nitrogen, the albumin nitrogen bearis a 
definite relation to the total nitrogen. This table shows the albumin 
nitrogen to constitute on the average 8.1 per cent of the total, and the 
only variation in this ratio that can be attributed to the period of 
lactation is the somewhat smaller proportion of albumin in the last 
3 or 4 week periods. 

Tablx 12. — Relation of the caseirij albumin, and residual nitrogen to the total nitroffeOf 

by 4^week periods. 



FKkMl 

Mo. 


Total 

nitrogan. 


Caasin 
nitrogan. 


nitn^EBn. 


Resldnal 
oitzogBD. 


Period No. 
No. 


Total 
nitrogen. 


Casein 
nitrog^b. 


Albomln 
nitrogen. 


Residnal 
nltzogBD. 


1 


Pereeni. 
100 
100 
100 
100 
100 
100 
100 
100 


PercenL 
82 
78 
80 
80 
81 
81 
81 
82 


Percent. 

9 
8 
8 
8 
8 
8 
8 


Percent. 
9 
18 
12 
12 
11 
11 
11 
10 


9 


Percent. 
100 
100 
100 
100 
100 
100 


Percent. 
82 
81 
88 
83 
84 
82 


Percent. 
8 
8 
9 
9 
7 
6 


PercenL 
10 


2 


10 

11 

12 

13 

14 

Avaraga 


11 


8* 


8 


4. 


8 


5^ 


9 


6. 


12 


7 




8. 


100 


81.4 


8.1 


11 







THB RESIDUAL NrTBOGEN. 



Under this term as here used is included the mtrogen remaining 
in solution after that precipitated as albumin is removed by filtering. 
The chemical nature of ^e nitrogen compounds included in this 
group will not be considered* 



48 



STAGE OF LAGTATIOK AND PB0PEBTIE8 OF MILK. 



Below ia giyen the average residual nitrogen for the 11 cows by 
4-week periods: 





Period. 




1 


2 


8 


4 


6 


6 


7 


8 





10 


11 


13 


oaliiitiogBa.. 


aoM 


0.063 


0.068 


0.068 


aQ66 


a066 


0.064 


0.060 


0.068 


a066 


a066 


0.0B8 



It will be observed that this amount does not show any variation 
that can be ascribed to the period of lactation. The total amount is 
slightly more than that classed as albumin. 

RATIO OF PROTEINS TO OTHER OONSTITUENT8. 

Table 12 also gives a summary of the relation of the casein nitrogen, 
albumin nitrogen, and residual nitrogen to the total nitrogen. On 
the average 81.4 per cent of the total nitrogen ia present as casein, 
and, as already pointed out, this ratio shows but little variation 
during the lactation period. The mtrojgen determined as albumin 
varies from 7 to 9 per cent of the total and the residual nitrogen 
averages 1 1 per cent of the total. 

Table 13 shows the relation between the total protein and the 
sugar. We find that the ratio of the sugar to the total protein 
increases during the first 10 or 12 weeks, reaching the maximum, as a 
rule, in the third month. From this period there is little change until 
the ninth month, when the ratio rapidly becomes narrower to the end 
of the period. This change is brought about by the fact that the 
per cent of sugar remains practically constant, while the total protein 
changes considerably during the lactation period. The data given 
indicate that the per cent of sugar does not follow the variation of the 
nitrogen and seems to bear no special relation to it. On the average 
there is found 1 .45 pounds of sugar for each pound of protein. 

Table 13. — Average ratio of sugar to total protein^ by 4^week periodt. 



talod. 


Total 
inotain. 


Sugar. 


Ayen0B 

for?^ 

JetBsyB, 


AT€faflB 

forS 

Hol- 

stalns. 


Avcrasa 
flar2 
Ayr- 

shra. 


•or 7^ 
BborU 

hOfllB. 


AvHan 
tor 

UOOIVB. 


1 

2 

3 

4. 

6. 

«• 

7 

8. 

9 

10 

U...... 

12 

18 


1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 


I. BO 
1.48 
1.41 
1.43 
1.87 
1.84 
1.29 
1.80 
1.28 
1.22 
1.22 
1.19 


1.44 
1.09 
1.00 
1.01 
1.07 
1.02 
1.64 
1.60 
1.49 
1.80 
1.24 
1.10 
1.18 


1.47 
1.64 
1.08 
1.81 
1.68 
1.86 
1.66 
1.08 
1.42 
1.94 
1.46 
1.89 


1.68 
1.00 
1.74 
1.67 
1.40 
1.49 
1.45 
1.89 
1.17 
1.06 
1.11 


1.47 
1.68 
1.08 
1.66 
1.60 
1.46 
1.60 
1.45 
1.82 
1.22 
1.28 
1.22 
1.18 











\ BESULTS OF THB EXFEBIMENTS. 49 

FAT. 

Table 14 gives the per cent of fat for each cow by 4-week periods, 
and the same is shown graphically in figures 1 to 11. Figure 12 indi- 
cates the average change in the pef cent of fat for the 11 cows. An 
examination of the weekly tables in the appendix will show wide 
variations with individuals and at different periods. Leaving these 
minor variations out of consideration, the normal variation during the 
lactation period may be studied. 

The data in the table show that there is a decline in fat during the 
first 3 months, followed by a period of from 4 to 5 months with little 
change. From this point on to the end of the lactation period the 
fat increases rapidly, reaching the maximum at the close. The results 
from practicaUy every cow agree with this general statement. It is 
generally recognized that as a rule the milk becomes richer in fat 
toward the end of the lactation period, but an error is conunonly made 
in assuming that this change is a gradual one from near the beginning 
of the TTiilking period. On the contraiy, there is little increase in the 
per cent of fat as a rule until that period is reached — ordinarily within 
2 months of the end of the lactation period — ^when a rapid decline 
begins in the quantity of milk produced. 

There are several factors that influence the per cent of fat in milk 
as consistently as does the stage of the lactation period, and these 
factors may even entirely overbalance the usual effect of advancing 
lactation. One of the authors has recently called attention to two 
factors that have such an influence. One of these is a variation that 
occurs with the season,^ which tends, in this climate at least, to cause 
a low per cent of fat in the middle of the summer and a higher in early 
winter regardless of the date of the beginning of the lactation period. 
The other is the influence of the physical condition of the animal.' 
If the animal carries a large amount of body fat at calving time, her 
milk during the first few weeks, when the body weight is declining 
from the absorption of fat from the body, will contain more than the 
normal amount of fat for that particular animal. This latter is prob- 
ably the explanation of the decline in fat observed in Table 14, which 
gives the results for the 1 1 cows used in this investigation. 

There is in general some relation between the amount of milk and 
the per cent of fat. When there is a sudden decline in the amount 
of milk secreted for any reason, as, for example, during sickness or on 
account of the animal having been moved to strange surroundings, 
the per cent of fat with few exceptions increases sharply. The same 

1 Eckles, C. H. JahresEdtliohe Schwankimgen des proaenttachea Fettgehaltes in Euhmlloh. If Qoii- 
wirtadiaftliches Zentnlblatt, toI. 6, No. 11, pp. 489-602. L«ipslg, November, 1900. 

sEcUeSfC.H. The Infloence of the tfttness of oow at pertoritlon on per cent of tet In milk. ICiasouri 
Xzperiment Station BnUetln 100. Columbia, Ko. , 1913. 

68223*»— BuU. 16^-13 i 



50 



8TAGB OF LACTATION AKD PBOPEBTIEB OF MILK. 



holds true in the rapid decline that occurs in the last portion of the 
lactation period. When the decline in milk secreted is gradual, as is 
the case during the middle part of the lactation period, there is no 
special tendency for the per cent of fat to increase. However, while 
it is safe to make this general statement concerning the influence of 
the period of lactation when conditions are normal and when a suffi- 
cient number of animals are included to eliminate minor variations, 
it must be borne in mind that individiial animals such as are found 
in commercial dairies may divei^e widely from this general rule owing 
to other factors or combinations of factors which exert a greater 
influence. 

Table 14. — Average per cent of fat for each cow, and breed average, by 4-tDeek periods. 



Cow No. 



4... 
99.. 
118. 



Average for Jeneys. 



206. 
206. 
209. 



Average for Holsteins.... 



900. 
301. 



AvOTage for Aynhires. . 



400. 
402. 
403. 



P.rf, 
6.17 
6.22 



6.20 



8.24 
8.07 
8.12 



P.Ct. 
4.63 
4.79 
6.31 



4.91 



3.14 



4.01 
8.87 



3.94 



Average for Shorthorns. . . . 
Grand total average. 



4.12 
4.66 

8.68 



4.06 



8.14 
2.88 
2.60 



2.87 



8.61 
8.741 



8.68 



4.09 
4.17 
8.38 



8.88 



4.00 3.86 



P.Ct 
6.07 
4.43 
6.56 



6.02 



8.02 
2.68 
2.74 



8.38 
8.81 



8.99 
8.97 
8.18 



8.71 



8.79 



& 



PM. 

4.86 
4.40 
6.11 



4.79 



8.26 
2.84 
8.24 



2.78 8.11 



8.861 
8.81 



8.60 8.69 



8.66 
8.80 
8.16 



8.54 



8.77 



P.Ct, 

4.81 
4.33 
6.51 



4.88 



8.29 
2.89 
8.14 



8.11 



3.32 
4.08 



3.70 
8.84 
8.14 



8.56 



8.82 



OQ 



P.Ct 

6.00 
4.22 
6.71 



4.98 



8.06 
8.06 
2.81 



2.98 



8.26 
8.78 



8.70 3.62 



8.60 
8.92 
8.13 



3.68 



3.79 



P.rt. 

4.73 
4.36 
6.09 



4.93 



8.26 
2.88 
2.94 



3.03 



3.80 
8.96 



8.63 



8.85 
3.98 
3.23 



3.09 



3.83 



I 



P.Ct. 

4.61 
4.18 
6.80 



4.83 



8.25 
8.00 
3.01 



8.09 



3.53 
8.94 



3.74 



8.73 
8.90 
8.55 



8.73 



3.85 



I 



P.Ct. 
4.73 
4.63 
6.17 



4.84 



8.15 
8.00 
8.01 



8.06 



3.74 
8.67 



3.71 



4.06 
4.67 
3.85 



4.19 



8.97 



I 



P.Ct. 

5.18 
4.98 
4.47 



8.31 
8.09 
8.52 



8.31 



4.52 
8.68 



4.06 



4.16 
4.42 
4.00 



4.19 



4.11 



H 



P.Ct 



5.62 
4.83 



6.23 



8.31 
3.40 
8.46 



8.39 



4.92 



4.92 



4.17 
4f65 



4.11 



4.22 



P.eL 



6.07 
6.28 



6.68 



8.49 



8.90 



8.70 



8.96 



8.96 



4.54 



P.Ct. 



6.48 



6.48 



8.68 



6.28 



4.48 



4.18 



4.18 



4.66 



P.efc 



6.47 



6.47 



8.68 



8. 68 



5.08 



RELATION OF FAT TO OTHEE CONSTrrUENTS. 

An examination of the data and the curves will show a similarity 
between the variation in the total protein and in the fat. While 
sudden variations in fat content from one milking to another are not 
accompanied by corresponding variations in the total protein, yet 
when the fat is permanently increased the protein is almost certain 
to be increased in the same proportion. While the ratio of fat to 
protein varies with individuals and breeds, it varies but little with 
the same individual from month to month. 



BESULTS OF THE EXPERIMENTS. 



51 



Table i5 is a summary of the influence of the stage of lactation on 
the fat, and the relation of the fat to total protein and casein. It 
will be observed that this ratio is fairly uniform. As compared to 
the average the total protein, as well as the casein, is low in the begin- 
Tiing in proportion to the fat, and increases gradually imtil it reaches 
the maximum near the end of the lactation period. This results from 
the fact that the total protein increases more during the progress of 
the lactation period, especially during the last four months, than 
does the fat. On the average there is 0.86 pound of total protein 
and 0.71 pound of casein for each pound of fat. This relation is of 
interest in connection with the buying of milk for cheese making and 
the use of milk for food. Figure 12 shows that the total protein is 
influenced more by the stage of lactation than is the fat. Even at 
the end of the lactation period the per cent of fat on the average is 
only 20 per cent above the mean, while the total protein increases to 
30 per cent above the mean. 

Table 15. — Relation of total protein and casein to fat, averaged by 4^week periodB, 



FBriod. 


Fat. 


Total 


Caaelii. 


Parts 
pro- 
tein 
fori 
part 


Parts 

casein 

fori 

ST 


Period. 


Fat. 


Total 
pro- 
tein. 


Casein. 


Parts 
pro- 
tein 
fori 


Parts 

casein 

fori 

part 

fat. 


1 


Peret. 
4.00 
3.86 
3.79 
3.77 
8.82 
3.79 
3.83 
3.85 


Peret. 
3.25 
3.06 
3.06 
3.13 
8.25 
3.26 
3.32 
3.32 


Peret. 
2.68 
2.36 
2.49 
2.49 
2.62 
2.68 
2.68 
2.74 


0.81 
.79 
.81 
.83 
.86 
.86 
.87 
.86 


0.67 
.61 
.66 
.66 
.09 
.71 
.70 
.71 


9 

10 

11 

12 

13 

14 

Average. 


Peret. 
3.97 
4.11 
4.22 
4.54 
4.66 
6.08 


Peret. 
3.67 
3.83 
3.89 
4.08 
4.34 
4.08 


Peret. 

2.87 
8.06 
3.19 
3.38 
3.04 
3.70 


0.90 
.93 
.92 
.90 
.93 
.80 


0.72 


2 


.74 


3 


.78 


4 


.74 


6 


.78 


6 


.78 


7 




8 


4:09 


3.53 


2.90 


.86 


.71 







Table 16 shows the relation between the fat and the sugar as 
influenced by the stage of lactation. It will be observed that from 
the first period to the second and third there is some increase in the 
ratio. The columns giving the amount of sugar and fat, however, 
show that this is due not to an increase in the sugar but to a decrease 
in the fat. 

The ratio remains practically the same from the second to the 
eighth period, after which it becomes considerably less, due to some 
decline in the amount of sugar and an increase in the per cent of fat. 



62 



STAGE OF LACTATION AND PBOPEBTIES OF HILK^ 
Tablb 16.— Relation o/mgar to fat, averaged by i-week periodi. , 



Period. 


Fat 


Sugar. 


Parts 
sugar for 


Period. 


Fat. 


Sugar. 


Parts 
sugar for 


1 


Percent. 
4.00 
3.85 
3.79 
3.77 
3.82 
3.79 
3.83 
3.85 


Percent. 

4.87 
4.84 
4.94 
4.82 
4.80 
4.75 
4.88 
4.83 


1.22 
1.30 
1.36 
1.31 
1.29 
1.30 
1.32 
1.28 


9 


Percent. 
3.97 
4.11 
4.22 
4.54 
4.66 
6.08 


Percent, 
4.62 
4.65 
4.74 
4.91 
4.70 
5.01 


1.20 


2 


10 


1.13 


8 


11 


1.16 


4 


12 


1 la 


5 


13 


1.0S 


A 


14 


L06 


7 


Average 




8 


4.09 

• 


4.80 


1.22 







The ratio existing between the fat and the total protein is sum- 
marized in Table 17. 

Table 17.— iJafio of fat to total protein, averaged by 4'^week periodi. 





Total pro- 
tein. 


Fat. 


Period. 


Average 
for 3 Jer- 
seys. 


Average 

for3Hol- 

steins. 


Average 

for 2 Ayr- 

shires. 


Average 

for3 8hortr 

homa. 


AveragB 
tor 11 

OOWSL 


1 


1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00 
1.00. 
1.00 
1 


1.68 
1.49 
1.44 
1.38 
1.32 
1.35 
1.34 
1.32 
1.29 
1.24 
1.29 
1.31 


1.04 
1.08 
1.04 
1.13 
1.11 
1.06 
1.05 
1.07 
1.00 

.867 
.917 
1.07 


1.14 
L19 
1.17 
L15 
1.19 
1.10 
1.17 
1.18 
1.06 
1.06 


1.21 
L20 
1.21 
LU 
1.06 
1.06 
1.06 
1.03 
1.10 
1.04 
1.05 


1.22 


2 


1.94 


3 


1.22 


4 


1.90 


6 


L17 


6 


L14 


7 


L15 


8 


1.15 





1.12 


10 


1.08 


11 


1.00 


12 




1.11 


13 






1.07 


14. 























SUGAR. 

Table 18 gives the per cent of sugar by 4-week periods for each 
cow, also an average by breeds and for the 11 cows. The curves in 
figures 1 to 11 show the changes in the per cent of sugar for each 
animal individually, and figure 12 illustrates the average for all the 
cows. The statements made by various authorities that the sugar 
is the least variable of the milk constituents except the ash seems to 
be borne out by the data here presented. The per cent of sugar is 
strikingly uniform as compared with the protein and fat. The only 
change that can be observed that seems to be brought about by the 
stage of lactation is a slight decline during the last 3 or 4 months of 
the period. This decline is marked with some individuals, while 
others are uniform or even increase slightly. The general average 
as weU as that for most of the individuals shows a slight decline, 
which seems sufficient to justify the general conclusion that the sugar 
runs practically uniform regardless of thd period of lactation, except- 



BESULTS OF THE EXPEBIMENTS. 



53 



ing that a decline of from 0.2 to 0.4 per cent may be looked for in 
most cases during the last 3 or 4 months. The increase of the total 
solids is not sufficient to account for this decline. If the -results are 
calculated on the basis of the water content the same small decline is 
found. 



Table 18. — Average percentage of sugar for each cow, and breed average, by 4'weeh 

periods. 



Cow No. 



4 

99 

us 

ATCnigB for Jawys.. 



ao5. 

206. 
209. 



Average for Hotateins. 



aoo. 

801. 



Average for Ayrshires. 



400. 
402. 
403. 



Average for ShorthomB... . 
Grand total average. 



P.CL 
4.80 
4.94 



4.92 



4.09 
4.07 
4.40 



4.39 



6.14 
5.17 



5.16 



5.40 
4.77 
5.21 



5.13 



4.87 



GD 



PM. 

4.99 
5.15 
4.47 



4.87 



4.98 
4.49 
4.00 



4.49 



4,81 
4.72 



4.77 



5.06 
5.32 
5.22 



5.20 



4.84 



I 



P. a. 

4.87 
5.17 
4.70 



4.91 



4.84 
4.44 
4.17 



4.48 



4.64 
5.62 



5.13 



5.44 
5.09 
5.39 



5.31 



4.94 






o 



P.et. 
5.28 
5.05 
4.56 



4.96 



5.18 
4.12 
3.95 



4.42 



4.87 
5.16 



5.02 



5.13 
4.72 
5.00 



4.05 



4.82 



t 



P. a. 

5.12 
5.04 
4.83 



5.00 



5.42 
4.26 
4.42 



4.70 



4.96 
4.77 



4.87 



5.87 
4.55 

458 



4.67 



4.80 



e 

I. 



CO 



P.et. 
5.00 
4.50 
5.21 



4.90 



5.37 
4.04 
4.36 



4.59 



4.57 
3.95 



4.26 



4.96 
6.09 
5.16 



6.07 



4.75 



I 

00 



P.et. 
4.39 
4.62 
5.20 



4.70 



5.20 
4.74 
4.16 



4.70 



4.82 
5.38 



5.10 



5.06 
5.29 
4.98 



5.11 



«I.8S 



I 



P.et. 
4.45 
5.14 
5.40 



5.00 



4.76 
4.25 
3.94 



4.32 



5.08 
5.13 



5.11 



5.19 
4.73 
5.11 



5.01 



4.83 



t 



p.<t. 

4.67 
4.62 
4.57 



4.62 



5.10 
4.09 
4.43 



4.54 



5.13 
4.85 



4.99 



4.65 
4.61 
4.06 



4.45 



4.62 



t 

5 



p.et. 
4.60 
5.03 
4.73 



4.79 



5.12 
3.94 
4.62 



4.56 



4.39 

4.88 



4.64 



4.22 
4.31 
4.17 



4.23 



4.55 



I 

i 



P.et. 



5.02 
4.90 



4.96 



5.13 
4.50 
4.79 



4.81 



4.89 



4.89 



4.25 



4.47 



4.36 



4.74 



i 

i 



P.eL 



5.61 
4.72 



5.17 



5.02 



4.15 



4.59 



5.04 



5.04 



4.91 



P.et. 



4.46 



4.46 



4.89 
4.*36 



4.60 



5.13 



5.13 



4.50 



I 



I 



P.et, 



5.22 



5.22 



4.81 



4.81 



5.01 



TOTAL SOLIDS. 

Table 19 gives the total solids. The stage of lactation causes much 
the same variation with the total solids as is tound with the fat and 
protein. First, there is a decline of about one-half per cent from the* 
first to the second month. From this time on to the eighth or ninth 
month there is little change. The rapid decline in milk during the 
last 3 months of the lactation period is accompanied by a marked 
increase in the total soUds. This general statement holds good for 
each of the 1 1 animals used in the investigation. 



54 



STAGE OP LACTATION AND PBOPEBTIES OF MILK. 



Table 19. — Average per cent of total iolids, for eadi cow and breed average, by i^wedt 

periods. 



Cow No. 



4 

99 

118 

Average for Jerseys 



206 

206 

Average for Ilolsteins. 



300. 
301. 



Average for Ayrshires. . . . 



400. 
402. 
403. 



AvOTage for Shorthorns 

Grand total average. 



P.ct. 
14.13 



14.13 



11.74 
10.95 
11.24 



11.31 



13.14 



13.71 
13.74 
12.85 



13.43 



12.74 



e 



P.et, 



13.09 
14.06 



13.50 



H.58 
10.10 
10.23 



10.64 



13.0712.27 
13.2012.60 



12.39 



13.29 
13.29 
12.16 



12.91 



12.26 



P.d. 



13. 
14.56 



3013 



13.93 



11.70 
10.18 
10.63 



10.84 



12.14 
12.67 



12.36 



13.05 
13.07 
11.76 



12.62 



12.29 



o 



P.eL 
14.44 
.15 



13.80 



1L95 
10.27 
11.07 



11.10 



11.81 
12.64 



12.23 



12.48 
13.07 
11.66 



12.37 



12.24 



P.ct 

14.28 
12.92 



13.60 



12.11 
10.54 
11.15 



11.27 



11.66 
13.09 



12. 3S 



13.06 
13.16 
11.66 



12.69 



12.35 



IS 



P.ct 

13.87 
13.04 
16.30115.16 



P.ct 
14.15 
12.76 



14.07 



11.77 
10.73 
10.96 



11.15 



11.35 
12.86 



12.11 



13.05 
12.97 
11.65 



12.56 



12.60 



14.02 



11.96 
10.75 
11.20 



11.31 



11.38 
12.63 



12.01 



12.96 
13.02 
12.77 



12.92 



12.61 






P.eL 
13.77 
12.81 
15.61 



14.06 



12.16 
10.80 
11.23 



11.40 



12.15 
12.64 



13.08 
12.03 
12.62 



12.84 



12.70 



I 



P.ct. 

13.63 
13.35 
14.79 



I 



P.ct. 

14.57 
14.27 
14.45 



13.9214.43 



11.05 
11.01 
11.68 



11.61 



12.56 
12.49 



12.4012.53 



13.03 
13. SI 
12.38 



13.07 



12.78 



12.20 



13.85 
11.78 



12.82 

12.43 
13.94 
12.90 



13.09 



13.16 



H 



P.ct. 



15.15 
14.42 



14.79 



12.12 

11.9013.30 

12.68 



12.83 



13.55 



13.56 
12.84 



13.19 



13.02 



P.ct. 



16.08 
15.08 



15.68 



12.2012.60 



12.9913.61 



13.01 



13.04 



13.04 



13.4614.04 



P.CL 



16.1017.16 



16.10 



13.04 



14.62 



13.78 



13.27 



13.27 



14.23 



o 



p.ct. 



17.16 



13.42 



13.42 



15.29 



Table 20 shows the average per cent of the total solids found as 
protein; casein, albumin, fat, and sugar, and the effect of the stage 
of lactation on this relation. The per cent of the total solids as ash 
is given for the general average only. On the average the total pro- 
tein represents 27 per cent of the total solids, and at the end of the 
lactation period constitutes about 3 per cent more than at the 
beginning. 

The casein increases slightly more than the total protein in per 
cent of the total solids. On the average this constituent makes up 
32.1 per cent of the total solids. Thd albumin averages 2.3 per cent 
of the total solids and shows a decline in relation to the total solids 
at the end of the lactation period. 

The fat represents 31.3 per cent of the total solids and shows a 
smaU variation during the lactation period in the way of an increase 
of about 2 per cent of the total solids near the end of the lactation 
period. 

The sugar represents 37 per cent of the total solids on the average. 
The ratio is quite uniform until about the ninth month, when a decline 
begins which continues until the end of the lactation period. In the 
beginning the sugar constitutes 38.2 per cent of the total solids, and 
in the fourteenth period 32.8 per cent. The sugar, aa. already shown, 
remains practically constant until near the end of the milking period, 



BESULTS OF THE EXPEBIMENTS. 



55 



when it declines somewhat. At the same time the other solids in- 
crease rapidly. As a result the ratio of the sugar to total nitrogen 
drops to a marked degree. 

The ash, which shows practically no variation in amount during 
the lactation period, represents on the average 5.3 per cent of the 
total solids. 

Table 20. — Average per cent of total solids in the milk, and percentage as protein^ casein^ 

alhumin^fat, sugar, and ash, by i-week periods. 



Period No. 



1 

3 

8 

4 

5 

6 

7 

8 



10 

11 

12 

13 

14 

AYsnige 



Total 
solids. 



Percent, 
12.74 
12.20 
12.29 
12.24 
12.36 
12.50 
12.61 
12.70 
12.78 
13.16 
13.46 
14.04 
14.23 
15.20 



13.06 



Water. 



PereenL 

87.74 
87.71 
87.76 
87.65 
87.50 
87.39 
87.30 
87.22 
86.84 
86.55 
85.96 
85.70 
84.71 



86.95 



Per cent of solids 



Protein. 



Percent. 
25.5 
24.9 
24.9 
25.6 
26.3 
2D.0 
26.3 
26.1 
27.9 
29.1 
28.9 
29.0 
30.4 
26.7 



27.0 



Caaeln. 



Percent. 
21.0 
19.2 
20.3 
20.3 
21.2 
21.4 
21.3 
21.6 
22.5 
23.2 
23.7 
24.1 
25.6 
24.2 



22.1 



Albumin. 



Percent. 
2.35 
2.34 
2.07 
2.06 
2.12 
2.14 
2.17 
2.11 
2.20 
2.33 
2.47 
2.54 
2.06 
1.88 



2.20 



Fat 



Per cent. 
81.4 
31.4 
30.8 
80.8 
80.9 
80.3 
30.4 
80.3 
81.1 
31.2 
81.4 
82.3 
32.8 
83.2 



31.3 



Soger. 



Percent. 
38.2 
39.5 
40.2 
39.4 
38.9 
38.0 
38.7 
38.0 
36.2 
34.6 
35.2 
35.0 
33.0 
32.8 



37.0 



Ash. 



Percent. 



5.3 



BELAITVE SIZE OF FAT GLOBULES. 

Table 21 gives the relative size of the fat globules for each coW; and 
figure 13 shows the average for the 11 cows expressed graphically. 






Flo. 13.— Relative sixe of f^t globules as infliienoftd by stage of lactation. (1) First 4-week period; (2) fifth 
4-week period; (3) ninth 4-week period; (4) thirteenth 4-week period. 

A determination such as this necessarily lacks the exactness of a 
determination like that for fat or nitrogen. However, 3 tubes were 
prepared from each sample and 3 readings taken from each tube 
according to the method given. An average of these 9 distinct 
counts for each sample reduces the variation to a minimum, and the 
further average of 4 separate samples, as given in the table, should 
give consistent results. It may be observed that the fat globules 
are especially large shortly after the beginning of the lactation period. 



56 



STAGE OF LACTATION AND PB0PEBTIE8 OF MILK. 



An examination of the weekly analyses in the Appendix will naake 
the extent of the variation in size of fat globules clearer. It will be 
seen that in every case the cows began their lactation period with fat 
globules in rdative size about twice the average for the milking 
period* The relative size declines sharply during the first six weeks^ 
remains fairly constant for five or six months, after which the decline 
is much more rapid to the end of the lactation period. 

It should be borne in mind that the relative size represents com- 
parative volume and not diameter. To represent the comparative 
diameters of the globules it is necessary to extract the cube root of 
the figures representing the relative size. ' 

In figure 13 the circles represent the comparative diameter of the 
average fat globules as found for the 11 cows during the first, fifth, 
ninth, and thirteenth 4-week periods. 

Table 21.— RelaHve nse of fat gMmUs in mUk ofeadi eoio^ and breed average, by 4^week 

periodi. 



Cow No. 



4... 
OB.. 
118. 



808 



ATCngB for JefB8]rs. 



206. 

aod. 

909. 



Ayerage for Hobtoins. 



800. 

801. 



Avcngo for Ajrrshires . 



400. 
402. 
403. 



ATBregB for SborttkomB... . . 
Grand total avenge. . 



242 



821 



656 830 825 



428 870 220 



1,280 



460 681 



147 



253 260 



130 



272 



236 



234 



185 



168 
180 



176 



442 

000 

867 



465 



603 
661 
808 



486 



857 401 



417 



871 



186 



148 
142 



146 



817 
804 
218 



274 
87g 



461 



148 147 
124 167 
186 138 



147 



185 
165 



245 
274 
183 



30H 334 



240| 



267 
264 
868 



206 



127 
184 
104 



122 



115 
165 



145 140 



260 
280 
134 



221 



266 200 



i 

I 



236 
840 
878 



82 

165 

80 



100 



133 
178 



200 
870 
801 



810 823 



107 

132 

08 



112 



168 



166 12X 



277 231 
232 271 



141 



217 



146 



216 



204 201 






818 
867 
334 






270 
836 



840 278 



06 

110 

00 



102 100 



80 
161 



107 
214 
147 



08 

06 

106 



76 
146 



116 111 



214 
213 
203 



186 210 



167 
200 
250 



00 
74 
70 



81 



120 
114 



122 



170 
103 
176 



263 
842 



212 808 



81 
70 
63 



146 



146 



104 



128 



182 161 



102 180 



815 
220 



272 



74 07 



03 



03 



162 118 166 110 



117 102 



76 118 



110 



110 



110 



It seems impossible to correlate the variation in relative size of the 
fat globules with the variation of any constituent of the milk. In 
the early part of the milking period a decline in the per cent of both 
fat and protein is accompanied by a decline in the size of the fat 
globules, while at the end of the lactation period the fat globules are 
the smallest and the fat and protein content are at the highest. 

It might be reasonably expected that the relative size of the fat 
globules would bear some relation to the physical constants of the 



RESULTS OF THE EXPERIMENTS. 



57 



fat. TaUe 22 gives the average, by periods, of the relative size, 
melting point, iodin number, Reichert-Meissl number, and saponifi* 
cation niunber in order that such a comparison may be made. 

The melting point rises as the relative size of the globules decreases. 
The change in the former, however, is not great, and a study of the 
weekly analyses shown in the table in the Appendix fails to indicate 
any special relation between these two characteristics in particular 
samples. 

What is said of the relation of the relative size to the melting point 
may also be said of its relation to the iodin number. From the first 
period to the second the iodin drops with the size of the fat globides, 
but as the fat globules decline toward the end of the lactation period 
the iodin number goes strongly in the opposite direction. 

The Reichert-Meissl number declines as the fat globules become 
smaller. The average results, as shown in Table 22 and in figure 14, 
seem to indicate a correlation between the size of the fat globules 
and the Reichert-Meissl number. An examination of the weekly sam- 
ples from the table in the Appendix seems to bear out this statement. 

Table 22. — RelatUm of size of fat glohuJes to physical constants of the fat.^Average 

determinations by 4'Week periods. 



Period No. 


Rela- 
tive 
8l£e. 


Melt- 
ing 
point. 


lodln 
num- 
ber. 


Relch- 

ert- 
MeisBl 
num- 

1)er. 


Sa- 
poni- 
fica- 
tion 
num- 
ber. 


1 


367 
307 
340 
386 
30O 
304 
301 


•c. 

81.78 
83.96 
83.83 
88.06 
83.38 
38.35 
83.33 


38.38 
81.68 
83.33 
8a 86 
31.86 
81.73 
33.96 


30.13 
37.40 
37.06 
36l46 
36.68 
36.40 
36.63 


383.7 
38a4 
38L0 
329.6 
339.3 
338.0 
336.7 


3 


3 


4 


6 


6 


7 





Period No. 


Rela- 
tive 
sice. 


Melt- 
ing 
point. 


Iodin 

num- 

ber. 


Reioh- 
ert- 
Meiasl 
num- 
ber. 


8 


103 

1^ 

163 
163 
166 
110 


•c 

83.41 
33.51 
33.04 
34.67 
88.86 
36.48 


33.36 
34.66 
35w41 
86.46 
86.17 
80.33 


36.30 
24.23 
33.48 
32.24 
2a 20 
17.30 





10 


11 


13 


13 





Sa- 
pon^ 
fica- 
tion 
num- 
ber. 



336.7 
326.6 
223.4 
223.8 
23a6 
316.6 



HELTINQ POINT. 

Table 23 gives details regarding the meltmg pomt of the fat for 
each animal. The same data are shown graphically in figure 14. 
With the exception of the last end of the lactation period, there was 
but little change in the melting poiut. The table in the Appendix 
gives the details of this determination by weeks. An examination 
of the table will show more clearly the variation that occurs at the 
b^inning and end of the lactation period. There seems to be no 
uniformity in regard to the changes that are foimd ui the melting 
point during the first few weeks of the lactation period. With three 
of the animalfl — ^namely, Nos. 301, 118, and 99 — there is a decided 
increase in the melting point from the first to the third week. With 
Nos. 205, 206, 300, and 400 there is a decided decline for the same 



68 STAGE OF ULCTATIOK AND PB0PEBTIE8 OF MILK. 

period, while the remainmg 4 show practically no change. The 
averages of all the cows by 4-week periods show an increase from the 
first to the second period. These variations in the melting point at 
this time can not be attributed to the feed, since that was uniform. 
It is probable that the explanation lies in the extent to which fat 
was taken from the animal's body to supply that produced in the 
milk. 

It has been found in other investigations not as yet reported that 
when an animal on account of insufficient feed declines rapidly in 
weight due to fat being removed from the body to support milk 
production, the melting point of this fat is raised, indicating that it 
has some of the characteristics of body fat. We also find that the 
fat produced during the first few days of the lactation period, during 
the stage before the milk is ordinarily used for food, always has an 
unusually high meltii^ point. It is also possible that these varia- 
tions in the melting point during the first week are influenced by the 
length of interval that elapsed before beginning the sample. The 
date of beginning the samples was governed by the condition of the 
cow, the plan being to begin as soon as the milk was deemed suitable 
for food purposes. In some cases the time that elapsed before the 
sampling was begun was only 5 days and in others as high as 10 days. 

After the first 3 weeks very little change is noted in the melting 
pomt until that point in the lactation period is reached when the 
milk flow declines very rapidly and when all the constituents show a 
decided tendency to change. This occurred at about 2 months 
before the end of the lactation period. In several cases the melting 
point rose as much as 6^ during the last 5 weeks, the most extreme 
figure being that for cow No. 205, where the melting point reached 
62.9^ C, while the average figure for the same cow was about 33^ 0. 

It is impossible to say what changes take place in the composition 
of the fat that result in this rapid rise in the melting point near the 
end of the lactation period. It is accompanied by a high iodin 
number and an especially low Reichert-Meissl number. An examina- 
tion in detail of the weekly analyses in the Appendix indicates that 
in most cases, for example, with cow No. 205, an extremely high 
melting point is associated with an unusually low Reichert-Meissl 
and saponification nmnber and a correspondingly high iodin number. 
This indicates that the decline in volatile acids, which have a very 
low melting point compared with the other fats, far more than offsets 
the increase in olein indicated by a high iodin number, which would 
tend to lower the melting point. On the whole, the melting point 
seems to be little affected by the period of lactation when the feed is 
kept uniform, except at the extreme end, when abnormally high 
results may be expected. 



BESULTB OF THE BXPBBIMENIS. 59 

Tablk 2S.^Avtrage nuUmg point oftht/atfor each eovi, and breed average, by 4-^eek 
perUiA. 



BEFRACTITE INDEX. 

The refractive index of the fat was determined as mentioned with 
the 2jeiss-Abbe refractometer under stand&fd conditions. This deter- 
mination was continued through the entire lactation period of 5 of 
the animals, and a number of determinations were made from sam- 
ples representing the milk of the others, llie results show a decided 
uniformity tmder all conditions. The determinations were finally 
dropped, since the variations found, due to the stage of lactation, 
were too smaU to be of any importance. The only variation that the 
data show at all is a slightly higher index in most cases during the 
first 2 or 3 weeks of the lactation period than was found during the 
remainder. We found no tendency for the refractive index to change 
during the last few weeks of the lactation period, as was found to be 
true of nearly every constituent of the milk, and also all the physical 
constants of the fat. 

BEICHBBT-HBI88L NCUBBB. 

Hie Reichert-Meissl number, or the volatile acid determination, is 

considered one of the most important of the physical constants in 

connection with butterfat. The results of this determination by 

' 4r-week periods are found in Table 24 and are shown graphically in 



60 



STAGE OF LACTATION AND PBOPEBTIES OF MILK« 



figure 14. In general there is quite a uniform decline from the 
beginning of the lactation period to the end, although this fluctuates 
with individual animals, as will be seen by inspecting the figures in 




FiQ. 14.— Variations in fat obanotan at end af eaeh 4-w«ek yeriod. 

detail. By eliminating these variations there ia a marked decline 
with the advance in period of lactation. 

The total number of determinations made was 484; the lowest was 
6.10 and the highest 33.38. The statement below shows the distribu- 
tion of these determinations from the lowest to the highest and the 
per cent of the whole number that come within limits of 5. 

Ftfoent 

Between 5 and 10 0. 8 

10 and 15 2.2 

15 and 20 4.5 

20 and 25 33.9 

25 and 30 50.2 

30 and 35 8.2 

Fifty per cent of the total number come between 25 and 30, while 
7.6 per cent of the total number come below 20. Bichmond con- 
siders butter with a Beichert-Meissl number less than 25 suspicious^ 



BBStTLTS OF THE EXPEBIMENTS. 61 

• 

and suggests that this number be adopted as the commercial limit. 
He also says that the absolute lowest limit must be fixed at 20. The 
statement given shows that 41.4 per cent of the determinations made 
were 25 or less, while 7.5 per cent went below the absolute limit as 
suggested by Richmond.^ 

The low figures here given are accounted for to a large extent by 
the fact that the cows were fed entirely on dry feed, while under 
conunerdal conditions fully two-thirds of the butter on the market is 
produced from animals that are consuming green feed; which is' as- 
sumed to give a higher Seichert-Meissl number. The further explana- 
tion of the large number of low determinations is the fact that each 
sample represents an individual cow, and toward the end of the 
lactation period when these abnormal samples occur the production 
of milk and fat is low. As a rule butter that comes on the market is 
a mixture of fat from several animals, and only under exceptional 
conditions would it happen that all were at such a stage of lactation 
as to give such an abnormally low Reichert-Meissl number. How- 
ever, it is entirely possible that such figures might be foxmd where 
samples of butter come from small lots made from a limited number 
of cows, and this possibility should be taken into account. 

The change in this constant, as is true with that of most of the 
others, is much more pronounced near the close of the lactation 
period, when the decline in milk production is rapid. As is the case 
with the melting point, variations in the Reichert-Meissl number 
during the first 5 or 6 weeks of the lactation period is irregular. In 
some cases there is a marked increase and in others a great decrease. 
The cause of this is probably to be explained in the same manner as 
was mentioned in connection with the similar variations of the melting 
point — ^that is, on account of the difference in the length of time repre- 
sented from the date of calving and the probability that in some cases 
the animal was drawing on the reserve fat of the body and using it in 
forming milk fat, while in other cases this was not done. 

The Reichert-Meissl number is more affected by the stage of lacta- 
tion than any other of the physical constants with the exception of 
the relative size of the fat globules. The marked similarity between 
the curve representing these two will at once attract attention. 

^ ^ g . . . 

^Richmond, Henry Dnwp. Dairy ohemlstry. London, 1800. See pb 382. 



62 STAGE OF LACTATION AND PEOPBBTIBS OF MILK. 

Tasib 2i.— Average ReiAal'Mfml ntanberfor weft ana, and breed merage, bff 4-vitek 



ATcngt for Jtmtji . . 



AvHaga lor H< 






AveragB fbc Bhorthoms 

Qnod taUl Bv«ng«. . . 



lODIN NUMBER. 

The iodin nmnber, or HQbl number, was determined according to 
die official method. The results of this detennination by 4-week 
periods are shown in Table 25. The average resulta for 11 cows are 
illustrated in figure 14. The total number of determinations made 
was 473, the lowest being 23.8 and the highest 49.4. The statement 
below shows how these detenninations are distributed between the 
minimum and maximum variations. It will be seen that 47.4 per 
cent of the whole lie between 30 and 35, and 93.8 per cent of all range 
between 25 and 40. 

Pdocnt. 

Between 20 and 25 0.4 

25 and 30 21.5 

30 and 35 47.4 

35 and 40 24. 9 

40 and 45 5. 4 

45 and 50 0.4 

With the beginning of the lactation period we find the same irregular 
results as mentioned in connection with the Reichert-Meisel number 
and the melting point. With 8 of the cows the iodin number declines 
from the first to the second month and in some cases the change is 
very striking. With 3 of the cows the change is the reverse from the 
first to the second month. The lowest point for the lactation period, 
according to the general average, is the fourth monthly period, after 



BBSULTS OF THB EXFEBIMBKTS. 63 

which there is & slight but gradual increase until to within 2 or 3 
months of the end of the lactation period. The iodin number 
increases as a rule gradually until it reaches the highest point 
during the entire lactation period. Since the iodin number repre- 
sente the olein, which is a soft fat with a low melting point, it would 
be assumed that an increase in this constituent of the fat would 
result in a decline in the melting point. The data given, however, 
show that in nearly every case the reverse is true. Even where the 
iodin number increases from an average of around 33 to 42 or 43, the 
melting point of the fat during the same period with some ii.nimii.lH 
increased as much as 15°. 

While there is no doubt that the tendency of the olein is to tower 
the meltii^ point, its inSuence is counteracted by the stronger influ- 
ence of the decline in the amount of butyrin. The melting point of 
butyrin is far below that of olein, and it therefore has a more marked 
effect upon the melting point. The amount of butyrin or butyric 
acid is indicated closely by the Eeichert-Meissl nimiber, and in all 
cases a high melting point is accompanied by a low Geichert-Meissl 
number, indicating that while a high olein usuaUy goes with a high 
melting point the butyric acid is 'at the same time abnormaUy low. 
This results in.a striking increase in the melting point, and these con- 
ditions are found mostly in the extremes of Uie lactation period, 
eapeciaUy near the end. 

Table 2S.—Avavge iodin nurrAtr for eadi etm, and bretd outrage, by 4-imk periodi. 



64 STAGE OF LACTATION AKD PBOPEBTIBS OF lOLK. 

8AFONIFI0ATION. 

The saponification or Koettstorf er number was determined accord- 
ing to the regular official method. Table 26 gives the results of this 
determination by 4-week periods for each animal. 

A total of 488 determinations of the saponification number were 
madC; among which the lowest found was 200.1 and the highest 252.3. 
The figures below show the range of variation expressed in percentage. 
About 81 per cent of the total number come between 220 and 235. 

Fttoent. 

Between 200 and 210 1. 6 

210 and 215^ 2.2 

215 and 220 G.0 

220 and 225 20.4 

225 and 230 84.2 

230 and 235 2a0 

235 and 240 4.8 

240 and 245 L8 

245 and 250 L4 

260 and 255 .^ 0.2 

The period of lactation seemed to exert a uniform effect upon the 
saponification value with all of the 11 cows. In general there was 
an almost uniform decline from the beginning to the end, with the 
exception that during the last 3 months the decline was most marked. 
This decline coincides closely with the decrease in the volatile acids 
as shown by the Reichert-Meissl number. Such a decline in the 
saponification number would be expected from the decline in the 
Reichert-Meissl number, since the low molecular weight of the vola- 
tile acids have the effect of holding up the saponification number, and 
when they are decreased a corresponding decline is expefited. This 
decline is so consistent and so uniform that it may be safely assumed 
that it is a natural effect of the period of lactation and may be looked 
for to show most in the last end of the lactation period, unless there 
is some other factor to iQterfere. The ratio 'between the saponifica- 
tion number and the Reichert-Meissl number is constant throughout 
the lactation period, which indicates that it may be a readjustment of 
the proportions of the higher fatty acids. 



BE8ULTS OF THE EXPEBIMENTS. 65 

Tablb 26. — Average taponification number /or each eme, and breed average, by i-vieeh 



Ash detenamationa were not made oa the 7-'day samples; they 
were prepared by combining 4 of these weekly composite samples. 
The total ash in this combined sample was determined according to 
the official method. The results may be seen in Tables 4 and 6. 

The amount of ash was found to be fairly uniform in all samples 
except that near the end of the lactation period there was Bome 
increase, which seems to be the only change that can be attributed 
to the stage of the lactation period. Our analyses did not include a 
determination of the several mineral constituents, which is of equal 
if not of greater importance than finding the total ash present. 

However, Dr. August Trunz,* at the University of Halle in 1903, 
conducted a very careful and complete investigation concenung 
these mineral constituents of milk as affected by the lactation period, 
and in order to make this bulletin more complete an abstract of his 
work is herewith incorporated. Full credit is given Dr. Tnmz for 
this work, and for complete details reference should be made to hia 
original article. Only tiiat part of his work which has to do directly 
with the ash will be discussed, although in his original paper he 
includes a study of other constituents. 

Dr. Tnuu'e inveetigBtioii was conducted with two cows. Cow 665 was k croai 
between a Simmenduler and a Norderditnmracher. She vm 3) yeani old at the 



66 STAGE OP LACTATION AND PBOPEBTIES OF MILK. 

beginniiig of the expenxneat, calved December 25, 1901, and went dry November 8, 
1902. She waa fed no regular ration, receiving the same feed as the rest of the hord 
which was dianged 2 or 3 times during the period. The other cow, No. 674, was a 
pure Friesian. She was 7} years old at the beginning of the experiment, calved 
January 14, 1902, and went dry December 6, of the same year. Since she was used 
for the production of baby milk her ration was kept uniform throughout the year. 
She received the following ration per 1,000 pounds live weight: 

Lucem hay pounds. . 16 

Barley straw do 8 

Oats do.... 8 

Linseed do 1 

Wheat bran do 2 

An analysis was made of the milk from each milking for 4 or 5 days after calving. 
After this, samples were taken at irregular intervals during the lactation period. 
Altogether 30 samples from each cow were analyzed. The total percentage of ash 
was determined as well as that of the various aeh constituents, which included KH}, 
Na/), GaO, MgO, SO,, PAi CI, and FeA- 

For the crude ash determination 40 to 50 grams of the milk were weighed into a 
platinum difdi, evaporated to dryness, and then ignited at low redness until a per- 
fectly white afih was obtained. The sample of aah for the determination of the indi- 
vidual constituents was obtained by evaporating about 1 liter of the milk in a nickel 
dish and igniting at low red heat. The soluble material, consisting largely of the 
alkaline chlorid, was extracted with hot water. The residue was then ignited at a 
somewhat higher temperature. Finally the two parts were united and evaporated to 
dryness in a platinum dish and then cautiously ignited and weighed. The aah 
secured in this numner was preserved in corked bottles until analyzed. 

For the determination of the individual constituents 2.5 grams of the crude ash waa 
weighed out, acidified with hydrochloric or nitric add, and made up to 250 c. c. 
Then 50 or 100 c. c. of the filtered solution, corresponding to 0.5 or 1 gram of ash, was 
taken for analysis. The hydrochloric acid solution was neutralized with ammonia, 
treated with ammonium acetate, warmed, the iron phosphate filtered off, ignited and 
weighed. Half of this was considered to be ferric oxid. 

From the filtrate, the calcium was precipitated as calcium oxalate and weighed as 
the carbonate and also as calcium oxid after igniting in the blast. The nuignesium 
was precipitated from the concentrated filtrate as magnesium ammonium phosphate, 
and after ignition weired as magnesium prophosphate. 

In another 100 c. c. of the solution the sulphuric add was predpitated as barium 
sulphate and the combined alkalies were determined in the filtrate as chlorids. The 
potassium was then determined by predpitation as potassium platinic dilorid and 
this calculated to potassium chlorid, subtracted from the combined chlorids to give 
the percentage of sodium chlorid. 

The phosphoric add was determined by the molybdate method and the dilorin by 
titration against ded-normal silver nitrate solution. 

The author distinguishes between crude and pure ash, the former being what is 
usually considered as milk ash and the latter obtained by subtracting from the crude 
aah the mineral constituents combined with the proteids. 

INDIVmUAL OOHPONENTB OF THE ASH. 

Sodium and potasnum. — Sodium and potassium imderwent great variations in the 
course of the lactation period. In the colostrum period the percentage of potassium 
was lower than in the remainder of the lactation period, the first milking containing 
16.15 and 17.08 per cent of Kfi in the total ash, which rose to 26.87 and 26.94 per 
cent at the time of the greatest secretion. It then fell slowly till the last two months, 
then rapidly to 16.89 per cent and 13.92 per cent at the end. 



DATA FBOM FIVE JEBSEY COWS. 67 

Exduding two figures which are abnormally high, the percentages of Na20 show 
variations from 3.24 per cent to 8.5 per cent of the total ash for one cow and from 4.32 
per cent to 8.56 per cent for the other. The tendency is for it to decline dmring the 
first half of the period and then rise during the second half. 

Calcium atid. — Excluding two abnormal figures, the calcium oxid varied between 
23.88 per cent and 27.49 per cent for one cow and between 21.23 per cent and 25.78 i>er 
cent for the other, being somewhat higher in the colostrum. The variations were 
erratic and showed but slight change during the period. 

Magnenum oxid. — ^The magnesium oxid varied from 4.52 per cent to 2.54 per cent 
and from 5.27 per cent to 2.51 per cent, &Jling during the first third and rising from 
then on to the end of the milking period. It was highest in the first milking of the 
colostrum. 

Chlorin, — ^The chlorin in the case of one cow remained nearly constant during the 
entire period, being from 11.5 per cent to 12 per cent. In the case of the other it rose 
from 11.86 per cent to 24.77 per cent. The chlorin content of the crude ash and of the 
pure aah seemed to vary somewhat in their relation to each other. 

Phosphoric add. — In the case of the two cows, the crude ash of the colostrum period 
contained 26.60 to 31.46 per cent and 28.28 to 31.45 per cent phsphoric acid, respec- 
tively. The pure ash contained a somewhat smaller percentage, 24.02 to 26.97 per 
cent and 22.25 to 28.36 per cent, respectively. 

With one cow there seemed to be irregular fluctuations which occurred at about the 
time of the changes in the food. The cow on the constant ration showed a gradual 
decline from an average of 30.36 per cent in the colostrum period to 25.58 per cent in 
the last 4 months, the last month showing a P2O5 content of 22.23 per cent. 

Iron and sulphuric add. — Iron and sulphuric acid were determined only to complete 
the analyses. They occur only in small amounts and do not undergo any considerable 
variation during the lactation period. Iron makes about 0.25 per cent to 0.5 per cent 
of the ash, and SO3 about 1.5 to 2.5 per cent. 

The author makes a distinction between the total nitrogen-contain- 
ing substance and the tot%l proteids, as will be noted in his tables. 
He determined the former by the ordinary Kjeldahl method and the 
latter by precipitation from the 10-times diluted milk by the addition 
of 15 to 20 c. c. of a solution made up of 190 c. c. 95 per cent alcohol, 
8 grams 25 per cent acetic acid, and 4 grams tannic acid. 

ADDITIONAL DATA FROM FIVE JERSEY COWS. 

In addition to the data from the 11 animals used primarily for this 
investigation, we are able to make use of less complete data from 5 
Jersey cows kept under somewhat different conditions. These 5 
cowS| which were registered Jerseys, are designated as Nos. 4, 43, 63, 
62, and 27. The conditions under which these animals were kept 
differed from the 11 animals supplying the other data in three particu- 
lars, as follows: (1) They were not kept on a uniform ration through- 
out the milking period; (2) they were maintained at uniform weight; 
(3) they were kept farrow. On the other hand, the 11 animals used 
especially in this investigation were fed on a ration of uniform compo- 
sition throughout the lactation period ; no attempt was made to keep 
the weight uniform, and they were not kept farrow. The 11 cows 
were kept under what would be considered ordinary commercial 



68 



STAGE OF LACTATION AND PBOPEBTIES OF MILK. 



conditions with the exception of uniformity in the ration. The 5 
Jersey cows all received the same grain nuxtm-e, which remained 
unchanged throughout the entire year. During the greater part of 
the year they were fed com silage and alfalfa hay, while for some 3 
months during the summer season the com silage was replaced by 
green alfalfa and green com. 

Composite samples of milk from the 5 Jersey cows were prepared 
by taking a definite number of cubic centimeters of milk per pound 
from each. These composite samples covered periods of 1 month 
each for Nos. 63, 43, and 4 and 10 days each for Nos. 62 and 27. 
Tables 27 and 28 give the analyses of these samples and the average 
weight of the animal for the periods represented. 

Tablb 27. — Data for 5 additional Jergey eow9. — Determinations for 3 oow9 from oomr 

ponte damples taken at SO-day periods, 

cow NO. 68. 



Tbirty days, ending— 


Ifilk. 


Fat. 


Nitrogen. 


Sugar. 


Aflh. 


Average 
weighL 


Oct. 26 


Pcunde, 
i 500.2 
641.4 
679.0 
663.3 
623.6 
620.9 
600.0 
463.3 
470.6 
419.9 
420.1 
323.0 
•118.6 


Percent, 
6.90 
6.22 
6.60 
6.40 
6.43 
6.36 
6.60 
6.28 
6.77 
6.67 
6.20 
6.40 
6.66 


PacenL 
a69 
.72 
.69 
.67 
.70 
.70 
.70 
.68 
.66 
.68 
.66 
.60 
*.67 


PereenL 
4.70 
8.83 


Percent. 
0.778 
.780 
.741 
.740 
.741 
.771 
.796 
.744 
.713 
.707 
.684 
.703 
.696 


Pcmnie. 
960 


Nov. 24 '. 


940 


Deo. 24. 


941 


Jmi- 23 


4.08 
4.36 
4.60 
6.06 
4.60 
4.40 
4.10 
4.63 
8.66 
4.28 


945 


Feb. 22 


938 


y[iir n 


941 


Apr. 22 


9S2 


May 22.. 


922 


Inmn,. 


939 


July 21 


959 


Aug. 20.. 


965 


Sept. 19 


974 


Oct. 2 


963 







COW NO, 43. 



Oct 25.. 
Nov. 24. 
Dec. 24.. 
Jan. 23.. 
Feb. 22. 
lCar.23. 
Apr. 22., 
10^22.. 
Tune 21. 
July 21.. 
Aug. 20. 
Sept 28. 



«020.6 


4.60 


0.57 


6.30 


a no 


776.4 


6.18 


.59 


6.45 


.770 


680.0 


6.42 


.66 


4.50 


.747 


674.8 


6.15 


.62 


4.66 


.615 


652.6 


6.86 


.56 


3.70 


.707 


669.6 


6.02 


.56 


4.10 


.712 


634.9 


5.20 


.65 


4.35 


.720 


616.6 


6.03 


.53 


4.60 


.728 


686.8 


480 


.66 


4.00 


.697 


619.0 


4.20 


.65 


4.78 


.664 


599.7 


4.20 


.67 


4.49 


.697 


« 500.8 


4.30 


.50 


8.89 


.609 



799 
811 
811 
803 
794 
808 
784 
792 
812 
812 
835 



COW NO. 4. 



Nov. 24 


• 1,206.4 
631.6 
643.6 
623.2 
622.4 
624.3 
4513 
464.7 
489.9 
476.5 
426.1 
• 161.7 


6.18 
6.67 
6.80 
6.96 
6.97 
6.10 
6.72 
6.40 
6.17 
4.67 
6.00 
6.20 


a63 
.64 
.62 
.62 
.65 
.63 
.66 
.67 
.64 
.66 
.68 
.70 


4.97 
8.83 


a842 
.768 
.800 
.760 
.791 
.792 
.702 
.661 
.787 
.684 
.782 
.731 


801 


Dec 24. 


817 


Jan. 23 


814 


Feb. 22. 


4.00 
4.20 
4.70 
4.60 
4.10 
4.41 
4.36 
4.16 
4.36 


813 


Mar. ^ 


814 


Apr. 22. 


807 


May 2? 


806 


June 21 


823 


July 21 


861 


Aug. 20 


837 


Sept 19 


%64 


Oct 5 


861 







>22daya. 



• 13 days. 



• 32 days. 



«34daya. 



• 48daya. 



• 16daya. 



DATA FBOM FIVE JEBSEY COWS. 



69 



Table 28. — Data for 5 additional Jeney cows — DeUrminationB for 2 cows from com- 

potiU samples taken at 10-day periods. 



COW NO. 62. 



Ten days ending— 


Milk. 


Fat 


Nitrogen. 


Sogar. 


Aah. 


Ayerage 
weigbL 


Oct. 15 


Pounde. 

116.9 

139.6 

147.3 

156.4 

150.2 

137.6 

135.2 

138.4 

134.9 

123.2 

119.4 

114.5 

112.0 

104.7 

104.8 

103.8 

98.8 

96.5 

87.9 

90.9 

84.4 

77.6 

72.6 

79.3 

73.0 

68.0 

65.5 

64.6 

56.2 

49.2 

46.6 

41.0 


Percent. 
5.14 
5.80 
5.20 
5.00 
6.30 
6.10 
6.60 
6.65 
6.10 
5.20 
5.60 
5.40 
5.55 
6.46 
6.30 
5.30 
6.20 
5.50 
5.10 
6.40 
4.95 
6.46 
5.30 
5.60 
5.30 
6.20 
6.30 
6.20 
5.20 
6.10 
5.00 
5.10 


Percent, 
0.63 
.63 
.63 
.62 
.62 
.63 
.63 
.63 
.65 
.62 
.62 
.63 
.62 
.66 
.66 
.65 
.63 
.64 
.66 
.60 
.58 
.64 
.61 
.60 
.62 
.64 
.63 
.60 
.69 
.68 
.60 
.60 


Percent, 
5.06 
4.85 
5.30 


Percent, 
0.763 
.764 
.761 
.770 
.765 
.760 
.761 
.708 
.768 
.700 
.760 
.767 
.754 
.759 
.700 
.712 
.735 
.778 
.786 
.720 
.657 
.837 
.800 
.916 
.723 
.732 
.665 
.718 
.686 
.6RR 
.000 
.688 


Pcunia. 
888 


Oct. 25 


883 


Nov.4 

Noy.l4 


882 

882 


NoY.24 


6.48 


884 


Dec. 4 


882 


Dec.l4 


8.93 
4.61 
4.55 
5.00 
4.23 
4.43 
8.03 
8.52 
6.18 
4.48 
8.88 
4.85 
4.61 
4.30 
5.00 
4.70 
4.40 
3.50 
4.60 
4.20 
4.40 
4.61 
4.58 
4.56 
4.60 
4.25 


880 


Bee. 24 


894 


Jan. 3 -r-w T 


806 


Jan. 13 : 


886 


Jim. 23... 


804 


Feb. 2 


806 


Feb. 12 


904 


Feb. 22 


903 


ICar. 3 


012 


Mar. 13 


906 


Mar. 23 


909 


Aiir.2 


007 


Apr. 12 


019 


Anr. 22 


913 


Hay 2 


910 


May 12 


010 


May 22 


919 


June 1 - r -.-- 


926 


Jnn«ll..,,,-- 


924 


June 21 . T . - r - - - T - r 


923 


Julyl 


931 




029 


Jaly21 


911 




897 


Auc. 10 


884 




906 







COW NO. 27. 



Oct 16 


1181.3 
292.6 
310.4 
826.5 
314.3 
289.2 
287.6 
288.0 
272.3 
274.9 
206.7 
240.5 
243.1 
234.6 
245.6 
243.9 
244.2 
235.0 
231.6 
242.3 
243.9 
236.6 
218.4 
222.2 
204.0 
191.1 
173.8 
194.3 
189.3 
182.8 
188.6 
182.2 
173.7 
184.9 
161.6 
162.6 
149.4 


4.20 
6.20 
6.60 
6.25 
6.30 
5.10 
6.60 
6.40 
6.10 
6.60 
6.10 
6.60 
5.80 
6.75 
6.60 
5.75 
6.70 
5.70 
6.60 
6.60 
6.60 
6.55 
5.60 
6.70 
6.00 
6.70 
6.70 
6.60 
6.40 
6.40 
5.00 
6.30 
6.70 
£.60 
6.60 
5.80 
6.00 


0.52 
.52 
.52 
.56 

.66 

.68 

.60 

.58 

.61 

.62 

.64 

.62 

.64 

.64 

.66 

.65 

.65 

.67 

.68 

.66 

.67 

.68 

.66 

.65 

.62 

.64 

.61 

.68 

.63 

.63 

.65 

.67 

.62 

.67 

.71. 

.70 

.69 


6.00 
4.70 
5.80 
5.00 


0.746 
.744 

.746 
.723 
.786 
.730 
.764 
.606 
.762 
.601 
.721 
.677 
.760 
.727 
.776 
.812 
.776 
.771 
.780 
.787 
.737 
.758 
.764 
.852 
.841 
.767 
.711 
.660 
.704 
.655 
.672 
.646 
.507 
.660 
.705 
.703 
.680 


024 


Oct 25 


867 


Nov.4 


840 


Noy.l4 


861 


Not. 24 


800 


Dec 4 


8.76 
4.40 
4.86 
5.03 
5.80 
4.80 
4.98 
4.83 
4.35 
5.08 
4.66 
8.90 
6.30 
4.96 
4.60 
4.00 
4.60 
4.60 


879 


Dec 14. 


873 


Dec 24 


861 


Jmi. 3. 


873 


Jan. 13 


865 


Jan. 33 


882 


Ptob.2 


865 


Feb. 13 


875 


Feb. 22.... 


872 


Mar. 3 


885 


Mar.l3 


883 


Mar. 23 ,. 


807 


Apr. 2 


888 


Apr. 12 


000 


Apr. 22 


903 


Ifoy2 


890 


May 12 '..'. 


903 


May 22 


914 


June 1 


924 


June 11 r . , 


4.70 
4.60 
4.67 
4.60 
4.80 
4.06 
4.60 
4.03 
4.68 
4.93 
3.79 
4.33 
4.35 


925 


Jane 21 


929 


Julyl 


926 


July 11 


932 


July 21 


899 


Joly31 


901 


Aug. 10 


906 


Al?ff.20 


928 


Ane. 30 


935 


8^0 


938 


8eptl9 


938 


Sept 29 


937 


Oct 9 


968 







> Only 6 days. 



70 STAGE OP LACTATION AND PBOPEBTIES OF MILK, 

EFFECTS OF MAINTAINING THE ANIMALS AT UNIFOBM WEIGHT. 

This group of 5 cows was kept, as stated, as near as possible at 
uniform weight. Each animal was weighed at a stated hour each 
day, and the ration increased or diminished in quantity as might seem 
necessary in order to keep it at a stationary weight. However, it 
is impossible with a heavy milking cow to prevent the weight from 
declining during the first few weeks of the lactation period. It will 
be noticed that in the case of No. 27 there was a considerable decline 
at this time and a smaller decline with Nos. 43 and 63. This decline 
in weight, which indicates a drawing on the reserve material in the 
body for milk production, may be reasonably expected to exert con- 
siderable effect upon the composition and properties of the milk, and 
this has been found to be the case. Some resulXs of it are noticeable 
in the tables presented. 

POSSIBLE VARIATIONS DX7E TO THE RATION. 

While the ration given these animals was not exactly the same 
throughout the lactation period and varied to a small extent as 
between the individuals, it is not believed that this variation was of 
sufficient extent to bring about any large change in the composition 
of the milk produced. 

EFFECT OF KEEPING THE COWS FAREOW. 

Keeping the cows farrow might be expected to account for con- 
siderable variation in results as compared with the 1 1 cows that were 
developing a fetus during the latter part of the lactation period. The 
tables show a marked uniformity in the composition of the milk 
throughout the lactation period with each of these animals. This is 
probably accounted for by the reasons given, and, furthermore, with 
the exception of No. 62 these cows were all still producing milk at 
the end of the 12 months included in the experiment. If the period 
covered by the investigation had continued untU the cows ceased to 
produce milk, it is probable that there would have been more change 
in the composition of the milk. Still, with No. 62, where the data 
include the entire lactation period, there seems to be little change in 
the composition of the milk in the last periods. It is well understood 
that as a rule an animal that is farrow continues to produce milk for 
a longer time than one that is pregnant. 

The smaller range of variation in the composition of the milk dur- 
ing the year for these 5 cows as compared with the 11 is due to the 
fact that they were farrow. The per cent of nitrogen remains prac- 
tically stationary with all 5 of the animals with the exception that 
in the case of No. 27 it is low in the first few periods. The probable 



DISCUSSION OF BBSULTS. 71 

cause of this is discussed on page 42. The per cent of fat, like the 
nitrogen, does not show much variation during the lactation period, 
there being no noticeable increase even at the end of the 12 months. 
The per cent of sugar remains fairly constant, and agrees with the 
data of the 1 1 cows heretofore given in declining to some extent in the 
latter part of the lactation period. There is no noticeable change 
in the per cent of ash, unless it be a slight decline. 

While the results as previously given for the 1 1 cows fairly repre- 
sent the changes that take place during the lactation period under 
normal conditions, the data of the 5 animals here under consideration 
assist in pointing out what factors are responsible for the changes that 
take place during the normal lactation period. 

GENERAL DISCUSSION OF THE RESULTS. 

It is evident from the data presented that certain changes in the 
composition of milk may be expected under normal conditions to 
occur during the lactation period. The lactation period in regard to 
its effect upon the composition of milk may be divided roughly into 
three parts. 

The first stage includes the interval from the time the secretion of 
milk begins until the composition reaches normal, and covers a period 
of from 3 to 6 weeks. After the birth of the calf the colostrum is 
first secreted, which contains, as is well known, an abnormally high 
per cent of protein and of ash. This extremely abnormal composi- 
tion changes rapidly during the first 4 days. Milk is ordinarily con- 
sidered to be fit for food about the fifth day, although the changes 
in the composition continue for some time. The per cent of total 
protein, as well as of fat, as a rule continues to decline for from 3 to 6 
weeks. One prominent characteristic of the fat during this first stage 
is the extremely large globules which are found in the beginning of the 
period and which decline rapidly in size during the first few weeks. 
During this first stage the composition of the fat also shows an irreg- 
ular variation from the normal. The iodin number is ordinarily 
higher than the average; likewise the Reichert-Meissl number and 
the saponification. As a rule the melting point is abnormally high 
during the first few days of the lactation period, but soon reaches 
normal. 

The second stage in the lactation period begins when the composi- 
tion of the milk becomes normal, and continues until a point is 
reached when a rapid decline in the quantity of milk produced begins. 
Ordinarily this occurs within about 6 weeks to 2 months from the end 
of the lactation period. The length of the second stage will depend 
upon the length of the time the cow produces milk, and to some ex- 
tent upon the quantity. If the complete lactation period of the cow be 



72 STAGE OF lAOTATIOK AND PBOPEBTIES OF MILK. 

10 months, this second stage will cover under average conditions about 
6^ months. During this interval the composition of the milk remains 
in general quite uniform. There is a slight increase in the latter part 
in the nitrogen and in the fat, but these are not marked. The sugar 
remains practically constant. The changes in the fat most notice- 
able are a gradual decline in the size of the fat globules, which is 
accompanied by a decline in the Reichert-Meissl number and in the 
saponification number. 

The third stage in the lactation period in some cases has a rather 
definite line of division from the second stage; in others the change 
is gradual. It begins at that point when the decline in milk produc- 
tion becomes rapid on account of the end of the lactation period 
being close at hand, and ordinarily this change begins from 6 weeks 
to 2 months before the end of the lactation period. During this third 
stage the composition of the milk changes widely from the average 
for the entire period, and while the extent of these changes varies 
with different animals, they are uniform to the degree that they may 
be reasonably counted on to occur under all normal conditions. The 
per cent of total protein rises rapidly, followed by the fat, although 
on the average the protein makes slightly the larger increase. Dur- 
ing this stage the total protein content may be one-third hi^er than 
that present during the middle of the lactation period. The casein 
and albumin remain in practically the same proportions. The fat 
undergoes marked variations at this time. The size of the fat glob- 
ules becomes very small, the melting point rises to a marked degree, 
the iodin number increases, the Reichert-Meissl number becomes 
abnormally low, and the saponification number likewise shows a 
strong decline. 

RELATION OF STAGE OF LACTATION TO USB OF MILK AS FOOD. 

In carrying on the investigations herein reported no attempt was 
made to determine how long after parturition milk is fit for human 
food. It is evident from the wide variations caused by the lactation 
period, especially in the per cent of protein present, that it is of con- 
siderable importance in many cases to consider the stage of the 
lactation period of the animal furnishing the milk in connection with 
its use as food. For infant feeding especially the amount of protein 
present is one of the important questions, and since a variation of 
one-third may be expected in the protein due to the stage of lacta- 
tion, this factor should be understood and taken into account in 
modifying milk for infant feeding. Where mixed milk of a herd is 
used wide variation due to this cause would naturally be less liable 
to occur, but where the source of supply is one animal or a limited 
number all in the same stage of lactation the importance of this 
factor as influencing the composition of the milk would be considerable. 



DISCUSSION OF BBSULTS. 73 I 



BELATION TO CHURNING. 

The plan for the investigation contemplated churning tests to be 
made at intervals in order to observe the effect of the stage of lacta- 
tion upon the time required for churning. However, many diffi- 
culties were experienced in working out a method to be followed 
in dealing with cream from individual animals and a satisfactory 
method was not evolved until the investigation was too far advanced 
to yield results of sufficient importance to be given in detail. The 
partial residts, however, corroborated the common observation that 
the milk of cows advanced in the period of lactation chums with 
difficulty. In fact, the cream from all the animals churned with more 
difficulty near the end of the lactation period, and with several the 
last few samples secured at the end of the lactation period could 
scarcely be churned at all. Samples from Nos. 205, 206, 209, and 118 
were foimd which we were unable to chum after trying every method 
we could devise. Persistent and violent shaking of this cream in glass 
jars at temperatures ranging from 10° to 30® C. failed to show any 
sign of churning after several hours of such agitation where cream 
under ordinary conditions would chum in a few minutes. The cream 
was also mixed with water and reseparated with a centrifugal sepa- 
rator to reduce the amount of soUds not fat, but the cream still refused 
to chum. 

The methods ordinarily followed in getting the samples of fat for 
analysis had to be modffied with these samples and the fat extracted 
with ether. All the samples that could not be churned were near the 
end of the lactation period. It was observed with tiiese same animals 
that the cream churned more and more difficultly as the end of the 
lactation period approached until the stage was reached when it 
became impossible to chum the samples. The conditions bringing 
about this difficulty in churning will be made the object of further 
investigation, but from tiie data at hand it appears that it was 
associated with a high per cent of protein and small fat globules, and 
it is believed these two factors together are the main causes of the 
difficulties experienced. 

ABNORMAL TASTE IN MILK AT END OF LACTATION PEBIOD. 

It was observed with cows 118, 99, 206, and 205 that near the 
end of the lactation period a strong abnormal taste and odor de- 
veloped in the milk within 24 hours after it was drawn from the cow. 
The flavor present might be described as a rancid and bitter taste 
combined. 

On June 17 samples of milk were taken from cows 209, 205, and 
403. The former two were near the end of the milking period and 
the latter near the beginning. These samples were cooled at once to 



74 STAGE OF LACTATION AND PBOPEBTIES OF MILK. 

10^ C. and placed in an ice box that maintained the above tempera- 
ture. Forty-eight hours later a slightly stale taste was observed in 
the milk of 209; that of 205 showed an extremely bad condition, a 
rancid, bitter taste strongly developed; the milk of 403 showed no 
abnormal taste. After 6 days the sample from 403 showed a slight 
acid coagulation and the mixed samples of 205 and 209 showed a 
hard coagulum floating on the surface. 

On June 18 samples were again taken from cows 205, 209, and 403, 
were cooled to 10° C, and placed in the ice box. Twenty-four hours 
later a slightly abnormal taste was observed in 209, while the same 
taste, but much stronger, was observed in 205; the sample from 
403 remained normal. 

June 19 further samples were taken from the three cows above men- 
tioned. No abnormal conditions could be observed in the samples 
when fresh, although a slight difference in flavor could be detected, 
making it possible to distinguish one sample from the other in this 
manner. An examination 14 hours later showed the sample from * 
No. 403 was still normal, while the mixed samples of 209 and 205 
had a slightly abnormal taste of the kind previously mentioned. This 
abnormal condition in the latter sample became rapidly worse. 

Accurate observations were not made regarding the milk of cow 
118, although the same abnormal taste was observed at the close 
of the lactation period. 

The cause of this abnormal condition of the yn^lk was not de- 
termined. The observations made showed conclusively that it was 
found only in the milk of certain cows near the end of the lactation 
period and that it was not in the milk when drawn from the cow, 
although even then the milk could be distinguished by taste from 
that produced by cows that were in the beginning or middle of the 
lactation period. The abnormal conditions described appeared within 
12 hours and continued to increase as the milk became older. The 
abnormal condition developed freely within 12 hours when the 
milk was cooled to below 10® C. immediately after milking and 
kept at that temperature. This latter statement suggests that it was 
not the action of bacteria, as at 10*^ C. any common organism will 
grow so slowly that a decomposition of the milk to the extent of 
producing a strong rancid odor and bitter flavor within 12 hours 
can hardly be expected. 

Numerous inq^es are received each year regarding abnormal 
flavor in milk from cows near the end of the lactation period. The 
conditions described in this correspondence indicate that the ab- 
normal taste and odor found in the milk of certain of the experi- 
mental animals is not uncommon in the milk of cows kept imder com- 
mercial conditions. 



SUMMABY. 75 

SUMMARY. 

1. Eleven purebred cows, consisting of 2 Ayrahires and 3 each of the 
Jersey, Holstein-Friesian, and Shorthorn breeds, were kept through 
an entire lactation period on a ration of uniform composition con- 
sisting of 2 parts of alfalfa hay to 1 part of grain. The latter was 
a mixture of 1 part oats, 1 part bran, and 8 parts cornmeal. This 
ration was varied in quantity to suit the individual animal. The 
cows were kept under normal conditions except in regard to the 
uniformity of the ration, and all remained in good health. The 
milk and fat produced were normal for the breeds. 

The object of the investigation was primarily to study the effects 
during a normal period of lactation upon the composition and prop- 
erties of the milk, disregarding changes that might be due to other 
sources. 

2. Composite samples were prepared from the milk of each cow by 

7-day periods. The following analyses and determinations were 
made : Specific gravity, dry matter, total nitrogen, nitrogen as casein, 

Xiitrogen as albumin, fat, sugar, and ash. The physical constants of 
the fat were determined as follows: Relative size of the fat globules, 
Beichert-Meissl number, iodin number, saponification niunber, 
refractive index, and melting point. The methods of the Associa- 
tion of Official Agricultural Chemists were followed. 

3. The total protein was found to be abnormally high following 
parturition and continued to decline until the third or fourth week, 
when the minimum was reached. It then remained fairly constant 
until near the end of the lactation period, when it rose rapidly and 
reached the maximum at the end of the period. The range in the 
total protein on the average was more than that for the fat. 

The casein constituted 80 to 82 per cent of the total protein and 
seldom went beyond these limits. It showed the same changes dur- 
ing the lactation period as described for the total protein. 

The determination of the nitrogen as albumin by the official 
method was unsatisfactory. Eliminating minor variations, the 
albumin bears almost a constant ratio to the total protein and there- 
fore follows the same variations during the lactation period. 

On the average, 81.4 per cent of the total protein is casein, and 
from 7 to 9 per cent was determined as albumin. No relation was 
found between the protein and the sugar. 

4. The per cent of fat on the average declined during the first 3 
months, followed by a period of 4 to 6 months with but little change. 
From this point a rapid increase was found to the end of the lacta- 
tion period. 

The variations in the fat and protein were on the whole quite 
similar. Sudden variations in the per cent of fat are, however, not 
accompanied by corresponding changes in the protein, but gradual 



76 8TA0E OF LACTATION AND PBOPEBTIES OF MILK. 

changes in the fat go with corresponding variations in the protein. 
On the average there is 0.86 pound of protein and 0.71 pound of 
casein to 1 pound of fat. Therefore, for each pound of protein on 
the average there wa6 found 1.16 pounds of fat. 

5. The lactose is the least variable of the constituents except the 
ash. The only change that is attributable to the stage of lactation 
is a sHght decline near the close. 

6. The total soUds show the same variation as the fat and protein, 
i. e.y a slight decline at first, then practically no change for 8 or 9 
months, followed by a rapid increase to the end of the lactation 
period. 

The total protein averaged 27 per cent of the total solids, the 
casein 22.1 per cent, the albumin 2.3 per cent, fat 31.3 per cent, 
sugar 37 per cent, ash 5.3 per cent. 

7. Ash determinations were not made on the 7-day samples. They 
were made by combining 4 of the 7-day samples. The amount 
of ash was quite imiform through the lactation period except near 
the end, when there was some increase accompanying the increase 
in the total solids. 

8. The milk of 5 additional Jersey cows was analyzed practically 
through a lactation period. The rations given these cows were not 
entirely uniform for the year. The cows were kept farrow and at a 
uniform weight. 

The range of variation in the milk of these cows was less than with 
those kept under normal conditions. The per cent of both nitrogen 
and fat remained practically stationary with no increase even at the 
end of 12 months. 

9. The stage of lactation exerts a marked and uniform effect upon 
the relative size of the fat globules. The fat globules are esp^ially 
lai^e immediately after the beginning of the milking period, then 
the relative size dechnes sharply during the first 6 weeks, remains 
fairly constant for 5 or 6 months, after which the decline is much 
more rapid to the end of the lactation period. Variation in the 
relative size can not be correlated with the variation of any of the 
constituents of the milk. The Reichert-Meissl niunber is the only 
physical constant of the fat that can be correlated in any way with 
the relative size of the fat globules. The data indicate that the 
small fat globules are accompanied by a low Reichert-Meissl number. 

10. The melting point of the butterfat was not ixifluenced to any 
great extent by the stage of lactation. During the first few wee^ 
there is a lack of uniformity in results, in some cases a high melting 
point in the beginning and in others a low. The high melting point 
in the beginning of the lactation period which occurs in most cases 
is probably brought about by the animal utilizing the body fat, since 
the ration fed at that stage of lactation is usually below the require- 



SUMMABY. 77 

ments of the body. After the first few weeks the melting point 
remaijis practically constant until near the end of the lactation 
period, when it rises. The rise in the melting point is accompanied 
by a high iodin number and an especially low Reichert-Meissl number. 
G^ the whole the melting point is little affected by the period of 
lactation when the food is kept uxiiform, except at the latter end, 
when abnormal figures may be expected. 

11. The refractive index was not affected to any appreciable extent 
by the stage of lactation. 

12. The Reichert-Meissl number showed a uniform decline on the 
average from the beginning to the end of the lactation period. Of 
the total number of analyses, 41.6 per cent came below 25, which is 
the standard set as a conunercial limit for butter, while 7.5 per cent 
of the total number came below 20. In the beginning of the lacta- 
tion period the variations in the Reichert-Meissl number were irregular. 
From this time on there was a gradual decline until near the end, 
when it became more marked. The Reichert-Meissl number is more 
influenced by the stage of lactation than any other of the physical 
constants except the relative size of the fat globules. 

13. The iodin niunber ranged from 23.8 to 49.4, while 47.4 per cent 
of the whole were between 30 and 35. A lack of uniformity is f oimd 
in the beginning of the lactation period. After this stage is passed 
there is a slight but gradual increase until near the end, when it 
increases more rapidly until the highest point is reached at the end. 

14. The stage of lactation exerts a uniform effect upon the saponi- 
fi.cation value. There is a uniform decline from the beginning to the 
end of the lactation period, with the exception that the decline is 
more rapid during the last 3 months. The decline is imiform with 
the decrease in volatile acids. The lowest figure among the 488 
determinatioxis was 200.1, and the highest 252.3, while 80.6 per cent 
of the total niunber came between 220 and 235. 

15. The churning of the cream became more difficult toward the 
end of the lactation period, and with some cows samples were found 
that could not be churned under any conditions. 

16. An abnormal odor and flavor developed in the milk of certain 
cows when near the end of the lactation period. This condition was 
not present in the freshly drawn milk but appeared within 12 hours, 
even when the milk was held at 10^ C. * 



APFBIIDOL 

Aa previouBly mentioned, a composite sample of the milk of each cow in this invee- 
ti^tion was tucen every 7 days. The detailed analyses of these 7-day samples for 
eSch of the 11 cows is given in Table I. 

Table l,-rAnalyn$ of the milk of each cow, by 7-day periods. 

COW MO. 4. 



T 



Week 




i 



I 



I 



i 



! 
I 



Mar. 



1006. 

Dec. 1 

8 

U 

22 

29 

1907. 

Jan. 6 
12 
19 
26 

Vab. 2 
9 
16 
23 
2 
9 
16 
28 
80 

Apr. 6 
18 
20 
27 

Kay 4 
11 
18 
25 

Jane l 

8 

16 

22 

29 

July 6 
18 
20 
27 

Aug. 8 
10 
17 
24 
81 

Sept. 7 



1.0900 
1.0810 
1.0840 
1.0640 
1.0320 



P. a. 

0.62 

.62 



P.eC. 
0.401 



P.d. 



1.0880 
1.0840 
1.0840 
1.0335 
1.0882 
1.0840 
1.0345 
1.0844 
1.0832 
1.0845 
1.0837 
1.0380 
1.0336 
1.0345 
1.0340 
1.0340 
1.0837 
1.0830 
1.0840 
1.0316 
1.0335 
1.0325 
1.0830 
1.0822 
1.0881 
1.0330 
1.0323 
1.0840 
1.0830 
1.0336 
1.0330 
1.0840 
1.0840 
1.0840 
1.0328 
1.0840 



.67 



.40 
.56 
.51 



.58 
.60 
.68 
.68 
.61 
.68 
.62 
.60 
.69 
.61 
.62 
.62 
.68 
.66 
.58 
.60 
.60 
.65 
.60 
.68 
.68 
.58 
.54 
.60 
.61 
.64 
.63 
.63 
■ 66 
.70 
.65 
.67 



.41 



0.062 
.006 



.40 
.40 
.84 



.46 

.47 

.61 

.47 

.49 

.61 

.491 

.46 

.48 

.48 

.49 

.60 

.47 

.47 

.40 

.47 

.60 

.42 

.49 

.47 

.47 

.45 

.46 

.47 

.60 

.51 

.60 

.50 

.53 

.53 

.61 

.53 



.069 



.048 
.058j 
.067 



.047 
.068 
.066 
.062 
.061 
.067 
.069 
.060 
.043 
.062 
.023 
.029 
.081 
.037 
.027 
.044 
.058 
.080 
.066 
.054 
.063 
.066 
.061 
.068 
.046 
.057 
.076 
.071 
.061 
.054 
.058 
.069 



P.ef. 
6.601 
6.37 
6.10 
4.02 
4.06 



4.85 
4.60 
4.60 
4.40 
6.10 
6.60 
6.17 
4.60 
6.07 



P.d. 



P.rt. 



P.cf. 



P.<*. 



86.87 



14.18 



9.61 



85.61 
4.661 85.601 
6.06 
4.93 



14.89 

14.40 

85.461 14.64 

85.60 14.41 



4.83 



85.6^ 
86.01 
85.82 



86.02 
86.16 
86.12 
86.24 
86.62 



4.80 85.74 

4.68 

6.02 

4.83 

6.14 

6.00 

4.97 

4.68 

4.77 

4.50 

4.38 

4.44 

4.26 

4.94 

4.80 

4.80 

4.67 

4.65 

4.85 

5.151 

4.82 

6.39 

Ik 68 



85.821 14.18 
14.26 



9.82 
9.74 
9.48 
9.48 
8.35 
9.46 



14.31 
13.99 
14.18 



85.89 14.11 



13.96 
13.85 
13.88 
13.76 
18.48 



86.39 18.61 



85.77 



14.23 



8.29 
9.16 
9.04 
9.11 
9.01 
9.17 
9.11 
9.26 
9.10 
9.17 
9.97 



4.80 
6.00 
4.88 
5.08 



6.40 
4.95 
4.51 
4.97 
4.87 
4.64 
6.00 
6.16 
6.22 
6.46 
6.22 
4.90 
6.10 
6.48 
5.00 
6.06 
4.88 
6.14 
4.95 
4.40 
4.63 
4.08 
4.44 



4.43 
4.26 
4.07 



86.04 
86.71 
85.97 
85.30 
86.45 
85.25 
85.20 



18.96 
18.29 
14.03 
14 70 
14.66 
14.76 
14.80 



9.89 
8.64 
9.18 
9.66 
9.73 
9.36 
9.12 



27.68 
82.06 
29.40 
27.88 
80.67 



27.43 
29.06 
27.72 
27.81 
28.05 
29.67 
28.65 
81.18 
27.80 
27.86 
27.22 
28.88 
80.26 
27.86 
20.32 
31.88 
28.53 
28.07 
28.32 
25.77 
21.89 
28.67 
29.54 
27.85 
27.83 
29.06 
20.77 



86.10 
82.18 
80.64 
25.48 
29.00 



25.16 
28.^ 
28.84 



28.14 
80.68 
80.06 
28.43 
27.90 
29.78 
33.64 
82.09 
87.96 
28.08 
27.96 
26.88 
27.93 
30.39 
26.93 
29.17 
83.72 
81.60 

>■•■•* 

29.69 
29.60 
29.88 
29.08 



881.2 
228.6 
283.4 

231.1 
230.8 



234.6 

286.2 

232.2 

233.8 

231.9 

231.6 

234.2 

233.8 

280. 

223.81 

229. 

230.4 

228.8 

232.4 

231.3 

280.6 

229.6 

224.2 

231.8 

229.2 

225.6 

227.2 

229.3 

228.5 

229.6 

229.9 

229.6 



1.40021 

1.4e( 

1.4B02 

1.4606 

1.4694 



1.4597 
1.4594i 
1. 



•c. 

83.851 
82.66 
88.86 
82.10 
82.86 



82.26 
88. U 

82.80 



264 
420 



441 



1.4698 

1.4676 

1.4506 

1.4604 

1.4508 

1.46961 

1.4683 

1.4600 

1.4500 

1.4607 

1.4606 

1.4591 

1.4688 

1.4606 

1.4501 

1.4681 

1.4506 

1.4506 

1.4572 

1.4603 

1.4501 

1.4594 

1.4608 



83.77 
82.65 
83.85 
33.41 
83.37 
33.06 
83.16 
83.17 
83.50 
83.08 
83.46 
83.27 
83.20 
38.30 
84.00 
83.30 
32.40 
83.16 
32.90 
33.16 
32.97 
83.66 
83.30 



366 



821 
218 
242 
207 
265 
883 
818 



166 
261 
241 
199 
250 
207 
474 
966 
840 
346 
217 



874 



4.68 26.76 32.91 

4.67 26.44 31.84 

4.83 24.62 82.66 

4.73 26.90 81.40 

4.88 25.81 31.42 

4.44 26.60 82.ea 

4.66 25.66 83.06 

4.42 86.87 82.18 



I 



227.8 
281.6 
244.4 
248.1 
240.2 
227.2 
230.6 
227.6 



1.4600 
1.4680 
1.4662 
1.4683 
1.4677 
1.4607 
1.4674 
1.4677 



32.90 
82.86 
88.86 
82.80 
32.80 
33.20 
38.62 
83.02 



108 
190 
161 
186 
184 
141 
189 
137 



78 



APPENDIX, 79 

Tabls l.—AnalytU o/'he mUt of each cow, bg 7-day period*— Continued, 
cow NO. w. 



STAOE OP LACTATION AND PBOPBBTIEB OP MILK. 
iLMl.—Jnalfti$efOuii»ilko/taeheow, by7-das ptnodt — Continued. 

COW NO. UB. 



APPENDIX. 



81 



Table I. — Analysis of ike mUh of each cowj by 7-day perioda — Continued. 

cow NO, 205. 



ending— s° 




1907. 

July 27 

Aug 3 
10 
17 
24 
31 

Sept. 7 
14 
21 
28 

Oet. 6 
12 
19 
26 

Nov. 2 

9 

16 

23 

ao 

Bee. 7 

14 
21 
28 

1906. 

Jan. 4 
11 
18 
25 

Feb. 1 

8 

15 

22 

29 

Ifv. 7 
14 
21 
28 

Apr. 4 
11 
18 
25 

May 2 

9 

16 

23 

30 

June 6 

IS 
20 
27 

jQly 4 
11 
18 
26 

Aqg. 1 
8 



1.0832 
1.0340 
1.0340 
1.0340 
1.0340 
1.0325 
1.0330 
1.0814 
1.0320 
1.0345 
1.0830 
1.0315 
1,0325 
1,0830 
1.0335 
1.0314 
1.0621 
1.0812 
1.0325 
1.0340 
1.0337 
1.0828 
1.0330 



1.0325 

1.0830 

1.0320 

1.0320 

1.0340 

1.0330 

1.0327 

1.0327 

1.0346 

1.0336 

1.0326 

1.0325 

1.0330 

1.0825 

1.0822 

1.0817 

1.0325 

1.0830 

1.0830 

1.0337 

1.0320 

1.0835 

1.03 

1.0335 

1.0834 

L0326 

1.0330 

1.0338 

1.0330 

1.0330 

1.0336 

1.0832 



P.cL 
a54 
.51 
.46 
.46 
.44 
.43 
,42 
.44 
.43 
.45 
.46 
.41 
.44 
.44 
.44 
.44 
.45 
.45 
.45 
.46 
.46 
.44 
.44 



P.ct. 
0.43 
.40 
.38 
.37 
.35 
.35 
.35 
.35 
.35 
.83 
.35 
.33 
.35 
.36 
.35 
.36 
.37 
.37 
.37 
.38 
.38 
.39 
.36 



.45 
.45 
.45 
.46 
.45 
.44 
.44 
.44 
.44 
.48 
.48 
.45 
.49 
.48 
.48 
.47 
.48 
.60 
.52 
.48 
.52 
.56 
.54 
.53 
.66 
.60 
.57 
.57 
.62 
.62 
.63 
.71 




.37 

.37 

.37 

.37 

.38 

.37 

.37 

.38 

.37 

.37 

.37 

.36 

.41 

.40] 

.89 

.38 

.40 

.41 

.43 

.41 

.45 

.42 

.47 



P.ct. 

0.048 
.039 
.049 
.029 
.034 
.028 
.040 
.026 
.025 
.033 
.042 
.025 
.080 
.033 
.029 
.036 
.031 
.032 
.036 
.037 
.033 
.032 
.031 



.46 
.48 
.52 
.47 
.55 
.66 
.66 
.60 



09 



.083 

.034 

.043 

.037 

.032 

.037 

.034 

.084 

.099 

.020 

.020 

.019 

.047 

.068 

.027 

.024 

.019 

.034 

.039 

.031 

.0351 

.035 

.031 

.034 

.051 

.030 

.019 

.032 

.017 

.017 

.083 

.030 



P.et. 
3.78 
3.19 
2.69 
3.30 
3.05 
3.14 
3.38 
3.00 
2.81 
3.01 
3.17 
3.07 
3.101 
3.10 
3.58 
3.21 
3.33 
3.34 
3.32 
3.17 
3.01 
3.30 
2.87 



e9 



P.et 

87.39 

87.92 

88.68 

89.05 

88.12 

88.20 

88.41 

88.97 

88.00 

88.33 

88.34 

88.54 

88.05 

88.36 

87.56 

88.24 

87.80 

88.05 

88.04 

87.66 

S8.34 

88.30 

88.23 



I 

■a 

O 



8.06 

3.54 

3.21 

3.38 

2.89 

3.26 

3.19 

3.38 

3.15i 

3.17 

3.19 

3.28 

2.94 

3.23 

3.36 

3.38 

3.261 

3.25 

3.27 

3.22 

3.50 

3.74 

3.20 

3.63 

3.40 

3.82 

3.68 

3.61 

3.61 

4.00 

3.52 

8.53 



88.04 
87.81 
88.24 
87.87 
88.17 
88.01 
87.90 
87.75 
87.60 
87.94 
88.06 
87.96 
88.26 
87.99 
87.90 
87.85 
87.80 
88.10 
87.73 
87.58 
87.81 
87.29 
87.30 
87.04 
88.36 
87.01 
86.97 
87.42 
86.46 
86.30 
86.51 
86.92 



i 

o 
a 

i 

QQ 



P.ct. 
12. Gl 
12.08 
11.32 
10.95 
11.88 
11.80 
11.69 
11.03 
12.001 
11.67 
11.66 
11.46 
11.95 
11.64 
12.45 
11.76 
12.20 
11.95 
11.96 
12.34 
11.66 
11.70 
11.77 



P.et. 
8.83 
8.89 
8.63 
7.65 
8.83 
8.66 
8.21 
8.03 
9.19 
8.66 
8.49 
8.39 
8.85 
8.54 
8.87 
8.55i 
8.87 
8.61 
8.64 
9.17 
9.65 
8.40 
8.90 



11.96 
12.19 
11.76 
12.13 
11.83 
11.99 
12.10 
12.25 
12.31 
12.06 
11.94 
1Z04 
11.74 
12.01 
12.10 
12.15 
12.20 
11.90 
12.27 
12.42 
12.19 
12.71 
12.70 
12.96 
11.64 
12.99 
13.03 
12.68 
13.54 
13.70 
13.49 
13.08 



to 



P.ct. 
3.98 
4.49 
5.24 
5.03 
4.94 
4.81 
5.01 
5.15 
4.99 

4. vv 

4.55 



8.90 
8.65 
8.56 
8.75 
8.94 
8.73 
8.91 
8.87 
9.16 
8.89 
8.75 
8.76 
8.80 
8.78 
8.74 
8.77 
8.94 
8.65 
9.00 
9.20 
8.69 
8.97 
9.60 
9.33 
8.24 
9.17 
9.35 
8.97 
9.93 
9.70 
9.97 
9.55 



22.95 
27.86 
29.32 
26.52 
24.97 



5.20 
5.26 
5.24 
5.03 
4.96 
5.09 
5.73 
5.91 
5.24 
5.18 
5.681 



5.48 
5.01 
5.57 
4.96 
5.27 
4.73 
4.50 
5.04 
4.75 
4.97 

■ • « * a 

5.32 
5.00 
4.87 
5.02 
5.45 
5.13 
5.32 
5.15 
5.10 
4.94 
4.82 
5.65 
4.63 
4.98 
4.78 
4.91 
4.78 
5.10 
5.17 
5.04 
4.22 



I 

g 

.a 
•g 



41.82 
30.81 
38.03 
37.83 
85.61 



27.34 
2&73 
26.23 
25.29 
28.05 
25.73 
24.45 
26.82 
27.49 
30.76 
29.71 
29.25 
27.92 
24.38 
27.35 
26.39 
25.92 



28.01 

26.72 

28.22 

28.88 

28.37 

27.01 

27.02 

28.63 

27.44 

28.96 

27.96 

27.78 

26.71 

27.88 

23.32 

26.72 

26.83 

2&62 

25.45 

27.14 

24.41 

2t83 

19.14 

21.78 

18.821 

14.72 

16.11 

12.61 

7.63 
10.06 

9.76 

iao9 



241.4 
244.2 
241.1 
229.1 



30.62 
37.40 
32.03 
31.65 
32.20 
36.15 
33.08 
31.89 
32.14 
30.30 
30.97 
31.27 
31.54 
33.29 
32.20 
32.77 
32.90 



32.68 
32.81 
32.73 
31.45 
33.60 
32.07 
34.46 
83.81 
33.46 
83.20 

3i'84 
36.16 
35.29 
37.69 
35.26 
83.94 
35.28 
34.98 
34.88 
36.44 
36.89 
38.71 
87.03 
37.48 
41.34 
42.07 
41.89 
44.96 
42.89 
41.61 
42.22 



229.1 

229.8 

231. 3t 

230.8 

230.6 

223.2 

234.1 

239.7 

230.2 

227.7 

235.1 

231.1 

229.6 

227.3 

231.3 

228.8 

227.1 



227.4 
228.0 
226.6 
227.3 
230.3 
229.1 



.3 

Is 






1.4595 
1.4587 
1.4606 
1.4005 
1.4574 



1.4603 
1.4680 
1.4549 
1.4543 
1.4579 
1.4665 
1.4575 
1.4662 



1.4577 

1.4554 

1.45761 

1.4571 

1.4572 

1.4668 

1.4573 

1.4571 



1.4573 
1.4557 
1.4672 
1.4564 
1.4571 
1.45701 



■4^ 

t 

I 
I 




36.53 
32.97 
32.17 
31.98 
32.60 



226.9 1.4664 



226.7 

225.3 

225.4 

225.3 

225.3 

224.1 

224.3 

220.2 

224.7 

226.3 

227.5 

225.1 

228.1 

224.51 

222.1 

219.0 

223.2 

219.0 

215.8 

215.01 

208.5 

200.1 

202.7 

210.7 

204.3 



1.4564 
1.4564 
1.4682 



33.45 
32.06 
33.25 
33.55 
33.67 
33.101 
33.52 
83.06 
34.55 
33.90 
33.06 
33.27 
33.07 
82.67 
82.88 
32.55 
32.06 



33.30 
32.75 
32.73 
33.80 
32.25 
32.73 
33.00 
33.10 
33.10 
32.75 
33.55 



83.48 
82.78 
34.25 
82.53 
83.80 
32.90 
82.85 
83.35 
82.95 
31.76 
32.85 
32.76 
33.30 
86.35 
86.15 



52.90 
50.26 
47.43 
47.33 



369 
197 
152 
248 
130 
176 
131 
151 
204 
142 
123 
124 
129 
183 
148 
127 
147 
128 
136 
96 
81 
72 
87 



116 

105 

120 

87 

112 

106 

85 

82 

126 

88 

87 

97 

88 

82 

113 

78 

88 

61 

75 

98 

90 

79 

227 

70 

59 

111 

112 

127 

177 

175 

186 



58223^— BuU. 156—18 6 



82 



STAGE OF LACTATION AND PBOPEBTIES OF MILK. 



Table I. — Analym of the milh of each cow, by 7 -day periocb— Continued. 

cow NO. 206. 



Week 

ending— 



1907. 
June 



July 
Aug. 

Sept. 

Oct 

Nov. 

Dec 



L0316 
1.0290 
1.0282 
1.0290 
1.0293 
1.0290 
1.0295 
271 1.0292 
1.0290 
1.0290 
1.0295 



8 
16 
22 
29 

6 
13 
20 

nr 

8 
10 
17 
241 1.03001 



31 
7 

14l 

21 

28 

5 

12 

19 

26 

2 

9 

16 

23 

3(M 

7 

14 

21 

2^ 



1.0275 
1.0282 
1.0275 
1.0290 
1.0300 
1.0300 
1.0290 
1.0290 
1.0290 
1.0300 
1.0278 
1.0286 
1.0281 
1.0290 
1.0290 
1.0290 
1.0295 
1.0290 



P.rt 
0.53 
.43 
.40 
.39 
.37 
.38 
.40 

% 

.38 
.87 
.37 
.38 
.38 
.40 
.40 
.42 
.42 
.39 
;44 
.42 
.42 
.43 
.42 
.41 
.40 
.40 
.42 
.42 
.40 



1906. 
JazL 4 

ir 

18 

25 

1 

8] 
15 
22 
29 

7 
14 
21 
281 

4 



F^b. 



Mar. 



Apr. 



1.0290 
1.0290 
1.0295 
1.0293 
1.0810 
1.0310 
1.0300 
1.0810 
1.0826 
1.0324 
1.0338 
1.0343 
1.0853 
L0846 



.46 
.45 
.43 
.44 
.45 
.44 
.45 
.49 
.53 
.56 
.65 
.68 



P.rf. 
0.41 
.34 
.31 
.30 
.30 
.29 
.31 
.29 
.30 
.30 
.29 
.28 
.28 
.30 
.32 
.31 
.301 
.31 
.35 
.32 
.83 
.82 
.83 
.34 
.31 
.31 
.30 
.32 
.33 
.32 




.84 
.34 
.33 
.35 
.36 
.88 
.88 
.41 
.45 
.44 
,52 
.54 
.68 
.61 






P.rt. 
0.0S8 
..036 
.038 
.037 
.029 
.036 
.019 
.029 
.025 
.035 
.026 
.034 
.022 
.028 
.0191 
.018i 
.033; 
.035| 
.020| 
.022 
.083 
.030 
.084 
.037 
.066 
.034 
.029 
.031 
.0321 
.030 



.037 
.046 
.040 
.036 
.030 
.038 
.034 
.028 
.048 
.045 
.044 
.047 
.073 
.095 



^ 



P.ct 

8.48 
8.17 
2.58 
8.C6 
8.00 
2.70 
8.19 
2.63 
2.76 
2.29 
2.70 
2.58 
2.94 
2.76 
2.96 
71 
10 
72 
2.94 
2.78 
8.06 
8.13 
8.01 
8.05 
8.05 
8.08 
3.01 
2.39 
3.08 
2.86 



P. a 

88.03 
88.96 
90.05 
89.16 



2.82 
8.23 
8.09 
8.13 
2.70 
8.06 
2.93 
8.35 
8.03 
8.08 
8.39 
8.44 
8.05 
8.73 



I 
I 

I 

6h 



P.rt 
11.97 
11.04 
0.95 
10.84 



89.90 
89.96 
90.38 
88.98 
89.96 
89.77 
9a 01 
80.73 
80.43 
89.43 
89.57 
89.33 
89.51 
89.60 
89.14 
89.20 
89.13 
89.18 
89.17 
89.06 
89.56 
89.37 
89.29 



89.00 
89.15 
89.13 
88.05 
89.07 
88.81 
88.72 
S7.90 
87.82 
87.97 
87.13 
86.91 



86.05 



10.10 
10.04 

9.62 
11.02 
10.04 
10.23 

9.99 
10.27 
10.57 
10.57 
ia43 
10.67 
ia49 
ia40 

ia86 

10.80 
10.87 
10.82 
10.83 
10.92 
10.44 
10.63 

ia7i 



11.00 
ia85 

ia87 

11.06 

ia93 

11.19 
11.28 
12.10 
12.18 
12.03 
12.87 
13.00 



s 



& 



P.et. 

8.49 
7.87 
7.37 
7.78 



I 



P.rt. 
8.88 
4.12 



4.21 
4.61 



7.47 

7.28 

7.38 

8.32 

7.46 

7.29 

7.23 

7.31 

7.86 

7.47 

7.71 

7.73 

7.71 

7.34 

7.73 

7.79 

7.82 

7.77 

7.75 

7.91 

8.051 

7.55 

7.85 



8.18 
7.62 
7.78 
7.92 
8.23 
&13 
8.35 
8.75 
9.15 
9.00 
0.48 
9.65 



18.95 ia22 



4.33 
4.54 
4.70 
4.48 
4.31 
4.25 
4.00 
4.06 
4.10 
4.80 
4.19 
4.82 
4.23 
4.28 
3.66 
4.14 
4.13 
4.24 
4.20 
4.91 
5.89 
4.45 
4.22 
4.79 



4.30 
3.60 
4.35 
8.58 
4.19 
4.23 
3.50 
4.06 
4.09 
4.09 
4.80 
4.68 
4.54 
4.48 



28.06 
28.47 
32.47 
30.69 
33.38 



28.80 
26.27 
26.38 
29.66 
28.31 
28.24 
24.70 
22.91 
27.60 
23.09 
25.56 
3a 63 
3a 23 
22.35 



24.70 
22.34 
26.49 
26.84 
25.89 
22.06 
22.29 
24.95 
2L46 



23.67 
23.49 
2a 80 
24.01 
25.41 
23.80 
28.06 
21.46 



17.73 
10.97 



15.27 



37.21 
29.80 
26.00 
29.02 



28.64 
34.06 
38.76 
34.24 
85.11 
34.00 
34.02 
27.60 
34.72 
3a 47 
29.80 
34.65 
32.58 
80.13 



31.96 
31.84 
81.21 
32.46 
31.90 
83.08 
85.16 
32.56 
88.54 



85.84 
35.06 
33.77 
84.76 
84.03 
38.06 
84.99 



86.66 
83.26 



87.02 
8&72 



P 

o § 
Ad 

OS 
CQ 



225.3 
234.8 
282.1 
229.3 



281.6 
223.9 
248.5 
247.9 
246.7 
231.4 
229.5 
235.4 
232.8 
236.9 
231.9 
233.1 
231.9 
232.6 



229.3 
232.2 
232.0 
232.6 
230.4 
228.8 
231.9 
229.2 
225.3 



223.7 
224.0 
224.2 
226.1 
222.6 
224.6 
222.6 
220.3 
21&2 
218.6 
223.4 
2ia4 
216.4 






1.4604 
L4505 
1.4S91 
1.4S01 



1.4505 
1.4574 
1.4569 
1.4508 
L4599 
L4570 
1.4579 
L4551 
1.4513 
1.4563 
1.4574 
1.4555 
1.4577 
1.4555 



1.4551 
1.4574 
L4576 
L4547 
L4572 
L4576 
L4582 
1.4574 
1.4574 



L4586 
1.4568 
1.4579 
1.4574 
1.4577 
1.4563 
L4560 
1.4588 
1.4587 
1.4563 



I 

7H 



34.06 
32.63 
81.76 
33.38 
32.45 



34.10 
34.02 
82.35 
81.38 
31.83 
32.20 



82.10 141 



82.47 
81.85 
82.30 
81.80 
81.82 
83.18 
33.07 

147 
83.061 106 



82.36 



38.66 
82.65 
33.06 
32.28 
33.55 
82.40 
32.56 
31.96 



84.26 
33.13 
62.10 
36.15 

34.80 



282 
250 
160 
304 
237 
439 
276 
128 
120 
126 
137 
114 



121 
140 
226 
174 
130 
122 



130 



32.00 147 

32.65 159 

32.40 120 

83.40 138 

82.20 112 

82.92 103 

83.88 108 



12S 

lOB 

123 

M 

74 

03 

61 

96 

79 

62 

84 

45 

64 

132 



APPBin)IX. 



83 



Table I. — Analysis of the mxLk of each cow, by y-day period$ — Continued. 

cow NO. 209. 



Week 



Sept. 



Oet. 



1907. 

July 27 

Aug. 3 
10 
17 
24 
SI 
7 
14 
21 
28 
5 
12 
10 
20 

Not. 2 

9 

16 

23 

30 

Dee. 7 

14 
21 
28 

1906. 

Jan. 4 
11 
18 
25 
1 
8 
15 
22 
29 
7 
14 
21 
28 

Apr. 4 
11 
18 
26 

May 2 

9 

16 

28 

30 

June 6 
13 
20 
27 

Inly 4 



Feb. 



liar. 



I.OSIO 
1.0S20 
1.0320 
l.Q8» 
1.0320 
1.0300 
1.0800 
1.0206 
1.0290 
1.0308 
1.0310 
1.0296 
1.0290 
1.0306 
1.0816 
1.0286 
1.0286 
1.0296 
1.0206 
1.0810 
1.0908 
1.0310 
1.0300 



1.0295 
1.0306 
1.0800 

i.oaoo 

1.0314 
1.0310 
1.0296 
1.0809 
1.0807 
1.0316 
1.0315 
1.0310 
1.0813 
1.0313 
1.0322 
1.0330 
1.0883 
1.0826 
1.0336 
1.0356 
1.0300 
1.0344 
1.0370 
1.0344 
1.0835 
1.0830 
1.0314 



P. a. 

0.61 
.49 
.44 
.45 
.45 
.43 
.44 
.46 
.43 
.46 
.47 
.44 
.49 
.46 
.46 
.47 
.44 
.45 
.43 
.47 
.47 
.46 
.46 




P.et. 
0.46 
.39 
.34 
.36 
.34 
.32 
.33 
.37 
.33 
.34 
.35 
.35 
.36 
.37 
.37 
.35 
.38 



.461 

.61 

.601 

.50 

.49 

.48 

.49 

.62 

.48 

.53 

.50 

.82 

.54 

.68 

.61 

.601 

.50 

.57 

.62 

.66 

.75 

.73 

.76 

.72 

.72 

.70 

.72 



.33 
.36 
.36 
.39 
.36 



el 



P.et. 

0.046 
.045 
.046 
.049 
.029 
.033 
.040 
.025 
.024 
.042 
.037 
.043 
.040 
.032 
.039 
.039 
.030 
.031 
.040 
.025 
.043 
.045 
.033 



.33 
.37 
.41 
.38 
.41 
.40 
.39 
.40 
.40 
.40 
.41 
.41 
.43 
.46 
.46 
.51 
.52 
.46 
.50 
.64 
.62 
.59 
.60 
.61 
.56 
.59 
.57 



.046 
.045 
.040 
.049 
.042 
.056 
.042 
.043 
.046 
.044 
.033 
.038 



.0591 
.061 
.063 
.053 
.044 
.079 
.056 
.074 
.062 
.083 
.084 
.066 
.100 
.083 



OS 



P.et 
8.05 
3.14 
2.50 
2.80 
2.40 
2.64 
2.68 
2.67 
2.54 
2.72 
2.96 
2.72 
3.92 
3.00 
3.09 
2.96 
3.00 
3.14 
3.35 
3.05 
2.54 
3.24 
2.73 



2.74 
3.00 
2.95 
8.06 
2.72 
3.15 
2.95 
3.08 
2.87 
2.94 
3.06 
3.18 
2.85 
3.69 
3.75 
3.32 
3.33 
3.29 
3.27 
3.52 
3.74 
8.75 
3.76 
4.06 
4.05 
6.54 
4.01 



1 

3 

O 
Eh 



P.et. 

87.16 

88.77 

89.56 

89.55 

89.80 

89.91 

89.78 

89.59 

89.01 

89.791 

89.37 

89.301 



P.et. 

12.84 

11.23 

10.44 

10.45 

10.20 

10.09 

10.22 

10.41 

10.99 

10.21 

10.63 

10.70 



49 



89.23 
88.61 
88.96 
89.19 
88.82 
88.79 
88.59 
89.19 
88.54 
89.07 



88.38 
88.80 
89.03 
88.56 
88.80 
88.66 
89.13 
88.61 
88.70 
88.47 
88.43 
88.41 
88.38 
87.51 
87.32 
87.39 
87.47 
87.72 
87.24 
86.80 
86.30 
86.30 
86.02 
86.44 
87.21 
84.39 
86.57 



10.77 

11.39 

11.04 

10.81 

11.181 

11.21 

11.41 

10.81 

11.46i 

10.93 



10.62 
11.20 
10.97 
11.44 
11.20 
11.34 
10.87 
11.39 
11.30 
11.53 
11.57 
11.59 
11.62 
12.49 
12.68 
12.61 
12.53 
12.28 
12.76 
13.20 
13.70 
13.70 
13.96 
13.56 
12.79 
15.61 
13.43 



P.et. 

8.89 
8.09 
7.85 
7.65 
7.80 
7.45' 
7.54; 
7.74 
8.45 
7.49 
7.67 
7.98 



i 
& 



p.et. 
8.89 
6.20 
4.17 
4.35 
4.15 
3.51 
4.14 
4.21 
4.001 



7.77 
8.30 
8.08 
7.81 
8.04 
7.86 
8.36 
8.27 
8.22 
8.20 



7.88 
8.20 
8.02 
8.36 
8.48 
8.10 
7.92 
8.31 
9.43 
8.59 
8.51 
8.41 
8.77 
8.801 
8.98 
9.29 
9.20 
0. 99 
9.49 
9.68 
9.96 
9.95 
10.22 
9.51 
8.74 
9.07 
9.42 



21.47 
24.23 
28.46 
28.45 



4.31 
4.20 
4.10 
3.38 
4.23 
4.10 
3.64 
4.33 
5.30 



4.03 
4.28 
4.50 



3.74 

3.88 

4.49 

3.96 

4.32 

4.20 

4.31 

4.06 

8.20 

4.17 

4.10 

4.64 

4.72 

4.37 

4.601 

4.99 

4.53 

4.84 

4.82 

4.97 

4.53 

3.57 

4.34 

4.33 

4.35 

4.06 

4.52 



43.11 
42.24 
86.82 
35.65 



26.82 
27.39 
26.32 
20.99 
24.30 
29.19 
25.92 
26.29 
27.14 
27.39 
27.37 
28.03 
25.71 
22.06 
23.44 
23.75 
26.70 



220.6 
239.0 
244.6 
244.4 



1^ 



I 



1.4587 
1.4606 
1.4606 
1.4604 



23.58 
22.62 
22.31 
24.35 
21.80 
23.99 
22.28 
24.15 



31.40 
36.16 
32.39 
34.01 
32.54 
32.13 
32.86 
33.51 
32.70 
33.09 
33.11 
32.48 
32.22 
36.05 
33.36 
34.74 
33.57 



36.42 
87.19 
36.97 
36.06 
36.22 
84.44 
35.88 
36.44 



22.78 
25.53 
24.10 
24.52 
20.31 
17.67 
20.90 
21.78 
22.84 
22.31 
21.36 
18.78 
22.28 
20.80 
20.60 
19.12 
21.34 
20.03 



36.78 



37.80 
36.46 
37.80 
42.47 
41.09 
o4. V4 

35.19 
33.06 
38.34 
84.82 
36.63 
35.51 
36.88 
37.74 
38.99 
39.06 



236.2 
223.4 
232.3 
234.1 
231.2 
230.5 
230.7 
232.8 
232.5 
227.4 
230.4 
232.2 
231.1 
223.3 
226.4 
232.0 
230.6 



224.4 
221.8 
225.7 
225.3 
223.3 
221.7 
218.5 
222.8 
226.6 
222.3 
224.5 
221.4 
219.6 
218.0 
212.9 
221.6 
224.2 
223.3 
222.0 
221.5 
221.0 
221.4 
223.2 
219.0 
217.5 
214.8 
215.8 



1.4602 
1.4601 
1.4562 
1.4664 
1.4559 
1.4572 
1.4565 
1.4576 
1.4577 



1.45661 

1.4571 

1.4579 

1.4582 

1.4570 

1.4575 

1.4673 



1.4575 
1.4582 
1.4580 
1.4576 
1.4558 
1.4579 
1.4565 
1.4573 
1.4563 
1.4579 




32.17 
83.85 
32.23 
82.08 



81.72 
32.70 
32.05 
33.40 
31.45 
32.55 
30.82 
31.15 
31.10 
83.23 
31.87 
32.75 
33.00 
84.07 
32.35 
82.12 
81.60 



81.35 
33.16 
82.06 
32.00 
32.00 
33.00 
32.75 
38.45 
31.93 
31.48 
83.35 
83.20 
83.88 
84.86 
84.80 
32.00 
33.03 
33.20 
32.40 
33.20 
33.80 
34.40 
84.86 
36.13 
37.40 
36.98 
37.80 



710 
237 
168 
174 
110 
128 
158 
158 
179 
122 
118 
123 
176 
133 
139 
104 

02 
120 
120 

86 

66 
114 

88 



87 
99 
94 

123 
74 

122 
72 
82 

119 

lis 

74 
78 
81 
78 
75 
86 
66 
60 
50 
66 
96 
63 
77 
66 
122 
114 



84 



STAGE OF LACTATION AND PROPERTIES OF MILK. 



Table I. — Analynt of the mUk o/eadi cow^ by 7-day period$ — Continued. 

COW NO. 300. 



Week 

ending— 



1908. 

Jan. 4 

11 

18 

26 

Feb. 1 

8 

16 

22 

20 

7 

14 

21 



Mar. 



Hay 



Apr. 4 
11 
18 
26 
2 

10 
23 

ao 

Jone 
13 
20 
27 

Inly 4 
11 
18 
26 

Aug. 1 

8 

16 

22 

20 

Sept. 6 
12 
10 
20 

Oct 3 



L0340 
1.0830 
1.0330 
1.0316 
1.0330 
1.0820 
1.0330 
1.0320 
1.0326 
L0820 
1.0830 
1.0320 
1.0814 
1.0302 
1.0312 
1.0306 
1.0304 
1.0313 
1.0320 
1.0316 
1.0801 



1.0302 
1.0302 
1.0306 
1.0290 
1.0304 
1.0296 
1.0300 
1.0310 
L0310 
1.0316 
1.0313 
1.0816 
1.0320 
1.0830 
1.0316 
1.0326 
1.0334 
1.0300 



P.eL 
0.61 
.53 
.60 
.48 
.46 
.40 
.48 
.46 
.47 
.40 
.48 
.49 
.60 
.46 
.46 
.47 
.46 
.44 
.47 
.46 
.46 
.48 
.46 
.49 
.47 
.46 
.46 
.45 
.49 
.47 
.49 
.61 
.53 
.68 
.67 
.68 
.61 
.641 
.71 
.72 



P. a. 
a49 

.44 

.43 
.40 
.40 
.38 
.41 
.401 
.40 
.40 
.40 
.38 
.41 
.37 
.36 
.37 
.37 
.38 
.40 
.40 
.39 
.38 
.37 
.40 
.39 
.38 
.39 
.41 
.42 
.44 
.44 
.47 
.40 
.63 
.62 
.63 
.55 
.67 
.61 
.61 




P.rt. 

a030 
.048 
.042 
.027 
.030 
.081 
.037 
.024 
.033 
.027 
.017 
.031 
.039 
.038 
.025 
.018 
.031 
.087 
.036 
.021 
.0201 
.042 
.024 
.026 
.041 
.0281 
.020 
.028 
.016 
.019 
.022 
.021 
.018 
.017 
.020 
.012 
.020 
.036 
.022 
.049 



4 



P.et. 
4.17 
4.32 
3.89 
3.65 
8.22 

3.65 

3.61 

3.31 

3.37 

3.45i 

3.38 

3.36 

3.50 

8.23 

8.36 

8.15 

3.47 

3.30 

3.35 

3.44 

3.40 

2.96 

8.20 

3.30 

3.46 

8.34 

3.11 

8.721 

8.50 

8.26 

8.65 

8.47 

3.61 

8.891 

3.99 

4.40 

4.58 

4.46 

4.65 



• 

I 



P.et. 
86.24 
86.61 
87.44 
87.43 
87.96 
87.60 
87.66 
87.72 
87.87 
87.72 
87.83 
88.02 
87.93 
88.11 
88.30 
88.43 
88.42 
88.04 
88.30 
88.02 
88.74 
88.02 
88.60 
88.66 



88.60 
88.66 
88.61 
87.70 
87.87 
88.11 
87.74 
87.93 
87.47 
87.24 
87.11 
86.64 
86.17 
86.08 
85.86 



P.tt 

13.76 

13.39 

12.56 

12.57 

12.04 

12.40 

12.35 

12.28 

12.13 

12.28 

12.17 

11.96 

12.07 

11.80 

11.70 

11.57 

11.58 

11.96 

11.70 

11.38 

11.26 

11.38 

11.40 

11.34 



11.40 
11.34 
11.39 
12.30 
12.13 
11.89 
12.26 
12.07 
12.53 
12.76 
12.89 
13.46 
13.83 
13.97 
14.14 



P.rt. 
9.59 
9.07 
8.67 
8.92 
8.82 
8.46 
8.70 
8.67 
8.82 
8.91 
8.72 
8.60 
8.71 
8.39 
8.47 
8.22 
8.43 
&49 
8.40 
8.03 
7.82 
7.98 
8.42 
8.14 



7.94 
8.00 
8.28 
8.58 
8.64 
8.63 
8.71 
8.60 
8.92 
8.87 
8.90 
0.06 
9.26 
9.52 
9.49 



P.et. 
6.561 
6.06 
6.16 
4.81 
4.74 
4.29 
4.95 
6.20 
4.99 
4.04 
4.24 
6.28 
6.14 
4.42 
4.98 
6.00 
6.02 
4.96 
4.90 
4.94 
4.65 



4.45 
4.62 
4.75 
4.79 
4.67 
6.06 
4.75 
6.22 
6.21 
6.13 
6.24 
6.12 
6.15 
6.00 
4.95 
4.83 
3.04 
3.74 



31.38 
28.45 
22.90 
27.89 
28.09 
29.23 
28.21 
29.60 
26.86 
27.12 
29.20 
27.84 
20.07 
24.12 
26.10 
26.76 
27.45 
26.31 
27.18 
26.38 



25.73 
25.80 
25.74 
23.64 
24.76 
24.63 
25.43 
23.93 
23.11 
24.01 
24.44 
24.96 
23.90 
23.25 
20.26 
19.09 
17.37 
17.43 



32.95 
34.88 
80.07 
32.42 
29.49 
28.25 
29.60 
27.47 
2&35 
25.95 
28.34 
28.12 
28.10 
36.72 



27.31 
29.65 
27.63 
26.61 



28.60 

29.86 

80.38 

31.88 

84.23 

37.87 

37.21 

37.26J 

89.37 

37.12 

85.54 

36.02 

34.91 

36.751 

33.66 

36.60 

36.99 

39.64 



p.a 



CD 



238.6 
228.6 
280.8 
231.3 
228.7 
230.2 
232.8 
231.0 
233.5 
233.7 
229.8 
232.0 
227.7 
223.3 
220.7 
227.6 
227.8 
227.9 
229.3 
231.6 



231.1 
329.9 
229.4 
227.6 
224.3 
224.1 
222.0 
221.3 
222.0 
221.9 
222.9 
220.9 
223.7 
228.2 
222.9 
219.3 
216.6 
216.7 



L4507 
L4575 
1.4565 
1.4570 
1.4544 
1.4663 
1.4549 
1.4566 
1.4557 
L4563 



t 
I 



•c. 

87.881 
83.68 
83.96 



83.30 
32.88 
33.56 
33.80 
33.50 
83.66 
33.36 
33.40 
83.78 
84.00 
83.60 
32.88 
83.70 
83.50 
33.78 
83.90 



83.88 
84.18 
83.56 
84.00 
34.48 
33.45 
33.40 
33.10 
33.90 
33.16 
33.06 
84.00 
82.88 
32.66 
33.75 
83.96 
84.90 
33.28 



173 
205 
175 
177 
160 
148 
199 
124 
141 
128 
157 
181 
123 
128 
130 
119 
106 
106 
146 
109 
116 

loi 

83 

U2 

94 

83 

63 

83 

76 

96 

86 

68 

70 

88 

170 

144 

129 

71 



APPENDIX. 



85 



Table I. — Anaiyns of the mUk of each cow, by 7-day periods — Gontinued. 

cow NO. 301. 



Week I 
endinS"- 



Feb. 



1907. 

Got. 6 
12 
19 
26 

Not. 2 

9 

16 

23 

30 

Dee. 7 
14 
21 
28 

1906. 

Jan. 4 

11 

18 

2S 

1 

8 

15 

22 

29 

7 

14 

21 

28 

Apr. 4 

11 

IS 

25 

nay J 

16 
23 
30 

June 6 
13 
20 
27 

July 4 
11 
18 
25 

Aug. 1 

8 

15 

22 

29 

Sept 6 
12 
19 



i 
I 

3 

o 



L0855 
1.0340 
1.0340 
1.0336 
L0340 
1.0317 
1.0811 
1.0338 
L0320 
1.0330 
1.0325 
1.0330 
1.0820^ 



1.0835 

1.0330 

1.0830 

1.0325 

1.0S20 

L0836 

1.0824 

1.0328 

1.0336 

1.0329 

1.0330 

1.0826 

1.0330 

L0321 

1.0320 

1.0312 

1.0814 

L0327 

1.0325 

1.0829 

1.0315 

1.0313 

1.0825 

1.0812 

1.0305 

L0306 

1.0316 

1.0303 

L0298 

1.0873 

1.0280) 

L0302 

1.0315 

1.0330 

1.0323 

1.0340 

1.0833 

L0376 



P. 
0. 



cL 
,64 
.67 
,54 
.50 
.40 
.50 
.50 
,49 
.48 
.49 
.48 
.47 
.60 



P.et. 
0.53 
.40 
.46 
.41 
.41 
.39 
.40 
.30 
.89 
.41 
.39 
.36 
.42 



.50 
.52 
.63 
.50 
.50 
.52 
.50 
.52 
.62 
.55 
.62 
.50 
.53 
.50 
.51 
.48 
.50 
.40 
.52 
.51 
.52 
.56 
.54 
.53 
.53 
.53 
.51 
.51 
.53 
.59 
.49 
.54 
.57 
.55 
.61 
.62 
.65 




P.et 
0.040 
.050 
.034 
.038 
.035 
.022 
.034 
.035 
.032 
.047 
.046 
.041 
.030 



.42 
.43 
.44 
.43 
.42 
.43 
.42 
.48 
.43 
.42 
.42 
.41 
.43 
.41 
.41 
.42 
.41 
.42 
.43 
.42 
.44 
.47 
.45 
.45 
.41 
.43 
.44 
.43 
.47 
.52 
.44 
.48 
.51 
.53 
.55 
.57 
.56 
.60 






p.et. 
4.11 
9. ov 
3.56 
3.90 
3.96 
3.58 
3.69 
3.71 
3.75 
3.83 
3.80 
3.85 
3.71 



.034 
.041 
.035 
.039 
.041 
.046 
.042 
.044 
.061 
.043 
.086 
.034 
.040 
.061 
.045 
.034 
.026 
.046 
.086 
.036 
.037 
.080 
.030 
.034 
.049 
.043 
.016 
.088 
.047 
.028 
.029 
.031 
.028 
.017 
.021 
.025 
.039 
.033 



s 

I 



p.et. 
86.29 
86.66 
87.06 
87.20 
86.98 
87.46 
87.63 
87.95 
87.64 
87.39 
87.36 
87.34 
87.26 



3.75 
4.01 
3.75 
4.12 
3.86 
4.24 
4.09 
4.00 
3.71 
3.66 
8.76 
4.07 
8.77 
4.00 
8.96 
4.16 
3.76 
3.76 
4.07 
3.55 
3.84 
8.61 
3.67 
3.71 
8.73 
8.46 
3.42 
3.34 
4.51 
6.83 
4.99 
8.96 
4.01 
3.87 
8.99 
3.76 
4.30 
4.48 



87.33 
87.20 
87.67 
86.89 
87.07 
86.69 
86.99 
87.26 
86.99 
87.23 
87.10 
87.10 
87.50 
87.74 
87.15 
87.62 
87.29 
87.33 
87.21 
87.14 
87.84 
87.91 
87.16 
87.66 
89.18 
88.07 
87.96 
88.10 
86.76 
84.21 
86.75 
87.29 
86.90 
86.93 
86.73 
86.95 
86.26 
86.08 



S 

s 

o 

Eh 



P.et. 

13.71 

13.34 

12.94 

12.80 

13.02 

12.54 

12.37 

12.05 

12.36 

12.61 

12.64 

12.66 

12.74 






o 
a 

2 

I 



P.et. 
9.60 
9.45 
9.28 
8.90 
9.04 
8.06 
8.68 
8.34 
8.61 
8.78 
8.84 
8.81 
9.03 



12.67 
12.80 
12.33 
13.11 
12.93 
13.31 
13.01 
12.74 
13.01 
12.77 
12.90 
12.90 
12.50 
12.26 
12.85 
12.38 
12.71 
12.67 
12.79 
12.86 
12.16 
12.00 
12.84 
12.34 
10.82 
11.93 
12.04 
11.90 
13.24 
15.79 
13.25 
12.71 
13.10 
13.07 
13.27 
13.05 
13.74 
13.02 



8.92 
8.79 
8.58 
8.99 
9.07 
9.07 
8.92 
8.74 
9.30 
9.12 
9.14 
8.93 
8.73 
8.26 
8. 89 
8.22 
8.95 
8.91 
8.72 
9.31 
8.32 
8.48 
9.17 
8.63 
7.09 
8.47 
8.62 
8.56 
8.73 
8.96 
8.26 
8.76 
9.00 
9.20 
9.28 
9.29 
9.44 
8.54 



i 



p.et. 
4.961 
5.35 
5.28 
5.11 
4.77 
4.91 
4.75 
4.44 
5.77 
5.67 
5.43 



5.34 



5.05 
5.14 
5.11 
4.96 
4.68 
4.44 
5.00 



4.23 
3.67 
6.83 
5.27 
5.00 
5.32 
5.32 
5.49 
6.22 
4.48 
5.00 
4.70 
4.88 
4.82 
4.62 
4.83 
4.70 
5.35 
4.63 
5.26 
4.90 
4.77 
4.94 
5.02 
5.04 
5.16 
5.34 
5.15 
4.90 



31.93 
32.03 
30.70 
27.70 
27.11 
27.95 
28.11 
25.19 
25.79 
25.88 
27.17 
27.48 
27.24 



24.75 
25.26 
23.28 
24.13 
24.71 
25.89 
24.79 
27.04 
26.64 
26.70 
26.76 
26.35 
26.15 
26.50 
24.34 
27.41 
27.18 
25.27 
25.72 
25.34 



26.88 
30.22 
26.92 
30.30 
27.87 
31.79 
29.90 
30.08 
31.31 
31.46 
30.70 
28.77 
29.16 



30.35 
30.00 
20.87 
30.58 
30.72 
81.19 
81.21 
30.39 
30.42 
30.11 



24.11 
23.80 
24.79 
23.37 
24.67 
24.59 
23.84 
21.83 
13.53 
13.14 
18.46 
23.55 
19.06 
25.79 
22.26 
21.17 
18.58 



82.99 
29.73 
29.58 
31.87 
31.76 
29.01 
8L57 
29.83 
31.25 



g 



11 

OQ 



238.0 
235.7 
238.9 
235.1 
235.5 
230.0 
232.3 
238.6 
232.6 
229.6 
233.1 
232.8 
232.8 



228.7 
229.2 
230.8 
225.9 
225.1 
230.4 
228.7 
229.0 
229.9 
232.0 
227.9 
218.1 
227.4 
226.2 
206.7 
226.2 
230.3 
228.7 
227.9 
23L9 



:S9 



I 



1.4555 
1.4565 
L4568 
L4567 
1.4669 
1.4574 
1.4571 
1.4552 
1.4568 
L4571 
L4572 
1.4565 
1.4569 



1.4564 
1.4562 
1.4565 
1.4568 
1.4568 
1.4561 
1.4553 
L4559 
L4561 
1.4575 



t 

I 
I 



l| 



P4 



33.81 
83.87 
32.37 
35.74 
36.33 
35.98 
87.56 
40.91 
49.44 
48.61 
44.01 
40.16 
38.28 
36.04 
36.48 
37.56 
36.36 



227.2 
226.2 
224.8 
223.9 
225.6 
222.8 
223.9 
227.1 
206.6 
207.3 
215.9 
217.9 
217.4 
223.5 
225.6 
218.7 
219.5 



•C. 

31.70 

31.02 

32.70 

31.95 

34.00 

32.80 

32.65 

33.40 

32.57 

32.07 

83.08 

32.70 

33.40 



33.00 
32.90 
82.90 
83.60 
84.85 
33.70 
33.23 
32.80 
33.48 
32.75 
32.90 
33.95 
33.90 
34.13 
33.95 
33.05 
33.65 
33.65 
33.85 
33.96 



32.69 
33.35 
84.45 
33.25 
83.00 
81.68 
32.66 
33.13 
36.23 
36.50 
32.75 
34.15 
32.80 



32.90 
83.25 
33.68 



227 
266 
204 
232 
281 
151 
157 
166 
137 
125 
164 
140 
152 



184 
171 
113 
146 
148 
206 
161 
126 
345 
122 
118 
116 
224 
164 
146 
136 
163 
159 
145 
118 
137 
153 
176 
134 
111 
91 
121 
98 
124 
212 
151 
86 
103 
87 
95 
93 
123 
115 



86 



STAGE OF LACTATION AND PBOPEBTIES OF MILK. 



Table I. — Analytii of the mUk of each cow, by 7-day periodi — Ck>ntinued. 

cow NO. 400. 



WMk 



1907. 

Oct. 12 
19 
26 

Nov. 2 

9 

16 

23 

30 

Dec. 7 
14 
21 
28 

1908. 

Jan. 4 
11 
18 
25 

Feb. 1 
8 
Ifi 
22 
29 
7 
14 
21 
28 
4 
11 
18 
25 
2 
9 
16 
23 
80 

June 6 
13 
20 
27 

July 4 
U 
18 
25 

Aug. 1 



Har. 



Apr. 



May 



1.0845 
1.0355 
1.0360 
1.0360 
1.0340 
1.0313 
1.0337 
1.0336 
1.0330 
1.0325 
1.0835 
1.0340 



P.CC 
0.57 
.54 
.53 
.53 
.51 
.52 
.52 
.50 
.48 
.47 
.44 
.45 



I. 

1.03301 

1.0340 

1.0328 

1.0331 

1.0351 

1.0340 

1.0350 

1.0346 

1.0334 

1.0337 

1.0843 

1.0350 

1.0340 

1.0340 

1.0332 

1.0337 

1.0344 

1.0346 

1.0347 

1.0326 

1.03X 

1.0340 

1.0328 

1.0310 

1.0300 

1.0307 

1.0300 

1.0290 

1.0900 

1.0303 



.46 

.47 

.49 

.51 

.51 

.52 

.53 

.56 

.53 

.54 

.56 

.55 

.55 

.55 

.58 

.55 

.56 

.55 

.56 

.55 

.55 

.59 

.60 

.50 

.59 

.60 

.61 

.581 

.61 

.59 

.58 



P.cfc 
0.47 
.45 
.45 
.42 
.41 
.43 
.42 
.39 
.39 
.38 
.37 
.37 



.86 
.38 
.39 
.40 
.42 
.44 
.44 
.45 
.45 
.43 
.44 
.44 
.47 
.45 
.43 
.44 
.45 
.45 
.47 
.48 
.43 
.46 
.46 
.46 
.46 
.48 
.50 
.49 
.55 
.51 
.54 




P,eL 
0.0601 
.056 
.047 
.046 
.053 
.061 
.050 
.047 
.014 
.041 
.047 
.030 



.030 
.045 
.039 
.0«8 
.044 
.062 
.055 
.020 
.068 
.046 
.030 
.038 
.057 
.064 
.063 
.042 
.037 
.052 
.050 
.045 
.048 
.045 
.044 
.046 
.051 
.049 
.028 
.022 
.028 
.031 
.021 



i 



I 



P.cL 
4.481 
4.07 
8.88 
4.03 
4.33 
8.95 
3.92 
4.17 
4.13 
4.31 
3.99 
3.54 



8.30 

8.99 

8.57 

8.73 

8.53 

3.02 

3.78 

^.55 

3.62 

8.72 

3.61 

8.79 

8.52 

4.07 

8.85 

3.95 

8.53 

3.90 

3.96 

3.53 

3.43 

3.91 

4.52 

4.35 

8.87 

4.781 

4.06 

8.91 

4.28( 

4.03 

4.20 



P.c*. 

85.841 
86.17 
86.40 
86.65 
86.42 
86.75 
87.02 
86.65 
86.42 
86.77 
87.13 
87.48 



87.95 

87.19 

87.89 

87.04 

87.09 

86.72 

87.06 

86.89 

86.83 

86.99 

86.99 

87.00 

87.31 

87.01 

86.82 

87.03 

87.12 

86.74 

86.66 

87.16 

87.60 

86.97 

86.52 

86.80 

88.31 

87.32] 

87.35 

87.30 

87.05 

87.21 

87.21 



s 
1 



P.rt. 

14.161 
13.83 
13.51 
13.35 
13.581 
13.25 
12.98 
13.35 
13.58 
13.23 
12.87 
12.52 



1^05 

12.81 

12.11 

12.96 

12.91 

13.28 

12.94 

13.11 

13.17 

13.01 

13.01 

13.00 

12.69 

12.99 

13.18 

12.97' 

12.881 

13.26 

13.34 

12.85 

12.40 

13.03 

13.48 

13.20 

11.69 

12.68 

12.65 

12.70 

12.95 

12.79 

12.79 



o 
a 



& 



P.el. 
9.681 
9.76 
9.63 
9.32 
0.25 
9.30 
9.06 
9.18 
9.45 
8.92 
&88 
8.98 



8.76 
8.82 
8.54 
9.23 
9.38 
9.36 
9.16 
9.56 
9.55 
9.29 
9.40 
9.21 
9.17 
8.92 
9.33 
9.02 
9.35 
9.36 
9.38 
9.32 
&97 
9.12 
8.96 
8.85 
7.82 
7.90 
8.59 
8.79 
8.67 
&76 
8.50 



P.CL 
6.64 
6.15 
5.30 
5.50 
4.28 
6.17 
5.06 
5.74 
5.47 
5.56 
5.40 
5.34 



5.01 
5.44 
5.04 
5.01 
4.98 
4.74 
4.75 
5.04 
5.39 
4.39 
4.58 
5.45 
5.28 
4.75 
4.87 
5.30 
5.44 
5.14 
5.09 
6.10 
4.68 
4.55 
4.54 
4.82 
4.46 
3.80 
4.24 
4.39 
8.90 
4.56 
4.29 






30.80 
29.43 
81.84 
80.91 
31.57 
31.64 
27.75 
26.26 
26.82 
27.68 
24.80 
25.49 



26.41 
37.41 
23.681 
37.44 

28.29 
29.07 
28.38 
28.56 



26.69 
26.12 
26.80 
24.02 
26.09 
23.40 
24.37 
25.41 
29.83 
24.13 
24.59 
28.17 
25.12 
94.81 
24.73 
28.33 
22.69 
28.01 
21.24 
22.00 
22.35 
22.41 



80.37 
28.40 
8L63 



81.12 
81.03 
80.80 
34.61 
41.04 
37.32 
87.91 
39.94 



39.97 
8X43 
81.65 
8L39 
81.23 
81.89 
81.69 
81.83 



82.74 
84.70 
32.50 
84.05 
88.43 
37.30 
88.04 
88.11 
83.92 
33.30 
82.66 
84.64 
33.46 
83.17 
35.84 
36.28 
85.64 
87.86 
37.86 
38.27 
38.44 
88.77 



280.1 
1 
1.5 
232.3 
236.2 
233.6 
230.6 
226.4 
222.8 
227.3 
225.9 
230.9 



286.8 

230.6 

227.6 

335.1 

228.2 

228.8 

232.3 

338.3 

331.6 

226.0 

324.1 

226.0 

226.6 

222.5 

223.01 

223.6 

225.1 

225.01 

227.5 

228.21 

225.5 

226.» 

226.1 

222.6 

220.3 

224.0 

218.2 

219.6 

216.1 

217.9 

216.5 



A 



L4663 



1.4678 



1.4566 
L4566 
1.4570 
1.4576 
1.4583 
1.4588 
1.4686 
1.4560 



1.45S8 

1.4562 
1.4572 
1.4558 
1.4552 
1.4566 
1.4655 
1.4657 
1.4561 
1.4675] 



83.90 
33.65 
83.30 
82.83 
32.85 
32.83 
32.75 
83.60 



284 



190 

274 



881 
340 
196 



317 
336 
302 
162 



186 



83.75 178 
84.20 450 
83.68 156 
84.00 
83.80 
83.60 
83. 1( 
83.55 
84.10 
84. 3f 
84.4C 202 
83.5fl 225 
83.90 203 
84.06 381 
86.3C 146 
35.85 
36.66 
86.66 
36.55 
87. 0( 
85. H 
86.60 194 



171 



119 
168 
194 
194 



I of the milk of each 
cow Nt 



APPENDIX. 87 

by 7-day periodi — Contiiiued. 



SI. SI 
J1.B7 

3t.2( 

'si'ae 

34. S3 
38.19 
24. S7 

sa.ifi 

34. £3 

33. 7S 
3$.K 



23. M 
22.39 
23.U : 

~e6 1.. 

as 37. 



STAGE OF LACTATION AND PHOPEBTIEB OF MILK. 
Tablb l.—Anal]/nt of the vvUh ofeaeh cov), lug 7-dag po-todi— Continued. 

cow NO.«B. 



■ -7 S30.*.. 

1 JJ7.1.., 

e 2».fl... 



ADDITIONAL COPIKB of tllli V 

■t\. aitj be pn>aar*d bomUic Ben 

— -T DoCDHnnB, OararmiiHit FifaUu 
WHhtagton, D. C, ■* '" -—' 



OOcB. Waabb^toii, D 



It 10 otota per copy 




to 



w 



laeoed January 18* 1918L 



U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 156. 



A. D. MEIVIN, Crii«F of Bcbeau. 









THE INFLUENCE OF BREED AND INDIVIDUALIH ON 
THE COMPOSITION AND PROPERTIES OF MILL 



BY 

C. H. ECKLES, 

Professor of Dairy Husbandry, University of Missouri, 

AND 

* ROSCOE H. SHAW. 

Chetnistt Daity Division^ Bureau of Anhnal Industry, 




WASHINGTON; 
GOVERNMENT PRINTING OFFICE. 

1913. 



..bja 



^M^^--L\ ^ 



iMued January 18, ISU. 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— BULLETIN 156. 
A. D. MELVIN, Chief o, Buujuj. 



THE INFLUENCE OF BREED AND INDIVIDUALITY ON 
THE COMPOSITION AND PROPERTIES OF MILK. 



BY 

C. H. ECKLES, 

Proltssar of Dairy Husbandry, UtiiversUy of Missouri, 

AND 

ROSCOE H. SHAW. 

Chentist, Dairy Division, Bureau of Animal Industry. 



BUREAU OF AIOMAL INDUSTRT. 



Chief: A. D. Mklvin. 

Assutant Chief: A. M. Farbinoton. 

Chief CUrh: Charles C. Carroll. 

Animal Hutbandry Division: Gboroe M. Rommel, chief. 

Biodiemic DioitUm: M. Dorset, chief. 

Dairy Divisum: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsay, chief. 

Meat Inspection Division: Rice P. Steddom, chief. 

Pathological Division: John R. Mohlbr, chief. 

Qiuarantine Division: Richard W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: £. C. Schroeder, Buperiatendent. 

Editor: James M. Pickens. 

DAIRT DIVISION. 

B. H. Rawl, Chief. 

Helmer Rabild, in charge of Dairy Farming Investigations. 

S. C. Thompson, in charge of Dairy Manufacturing Investigations. 

L. A. Rogers, in charge of Research Laboratories. 

Ernest Kelly, in charge of Market Milk Investigations. 

Robert McAdam, in charge of Renovated BtUter Inspection. 

2 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

Bureau op Animal Industry, 
WashingUm, D. C, July 11, 1912. 

Sir: I have the honor to transmit, and to recommend for publi- 
cation in the bulletin series of this bureau, the accompanying manu- 
script entitled **The Influence of Breed and Individuality on the 
Composition and Properties of Milk," by Messrs. C. H. Eckles, pro- 
fessor of dairy husbandry. University of Missouri, and Roscoe H. 
Shaw, chemist in the Daiiy Division of this bureau. 

The experimental work reported herein forms part of a series of 
cooperative investigations inaugurated in 1906 between the Dairy 
Division and the Missouri Agricultural Experiment Station, with the 
object of studying in detail the factors influencing the composition 
and properties of milk as produced under normal dairy conditions^ 
The first results of the work have been forwarded for publication as 
Bulletin 155, entitled ''The Influence of the Stage of Lactation upon 
the Composition and Properties of Milk." 
Respectfully, 

A. D. Melvin, 
Chief of Bureau. 

Hon. James Wilson, 

Secretary of Agriculture. 

3 



CONTENTS. 



Page. 

Introduction * 7 

Plan of the investigation 8 

Method of sampling and preparation of samples for analysis 8 

The true average per cent 9 

Results of the experiments 9 

Total solids 10 

Fat 12 

Total protein 14 

Casein. 15 

Relation of the casein to the fat 16 

Sugar 18 

The chemical and physical constants of the fat 19 

Relative size of the fat globules 19 

The Reichert-MeisBl number 21 

The iodin absorption number 23 

The saponification or Koettstorfer number 24 

The melting point of the fat 25 

Summary and conclusions 26 



ILLUSTRATION. 



Fig. 1 . Relative size of the fat globules in milk of dairy cattle 20 

5 



THE INFLUENCE OF BREED AND INDIVIDUALITY ON THE COM- 
POSITION AND PROPERTIES OF MILK. 



INTRODUCTION. 

In 1906 the Daiiy Division of the Bureau of Animal Industry, in 
cooperation with the Missouri Agricultural Experiment Station, 
began a series of investigations, the main object of which was to 
study in detail the factors influencing the cbmposition and proper- 
ties of normal milk. It is a well-known fact that although the 
same constituents are always present in milk, the relative amount 
of each is subject to constant variations. Among the causes of 
these variations are known to be the breed of the animal, the stage 
of lactation, the individuality, and to some extent the feed, the 
interval between the milkings, and the temperature and weather 
conditions. It is also known that the first and the last milk drawn 
differ in composition. 

A large amount of data has been published regarding these varia- 
tions, the greater part of which deals with the fat content alone. 
In planning this series of investigations it was arranged to give 
attention first of all to the variations occurring during the period 
of lactation. The data concerning this part of the subject have 
been prepared for publication as Bulletin 155 of the Bureau of Ani- 
mal Industry, entitled ''The Influence of the Stage of Lactation on 
the Composition and Properties of Milk." In carrying on this inves- 
tigation the plans were so arranged that the influence of breed and 
individuality of the animals could be studied concurrently with that 
of the period of lactation, and a presentation of these results is the 
object of the present paper. 

There is no lack of data concerning the influence of the breed and 
the individuality of the animal upon the composition of milk as far 
as the per cent. of the fat is concerned, although in practically all 
investigations reported there was no uniformity in the rations fed 
the animals and no data taken concerning the composition of the 
fat produced. When the influence of the stage of lactation is not 
taken into account, and when the ration is changed from time to 
time or varies with different animals, it is clearly impossible to state 

64010^— Bull. 156—13 2 7 



8 INFLUENCE OP BREED AND INDIVIDUAUTY ON MILK. 

to what extent any variation found may be due to the ration fed 
and to what extent to the stage of lactation, breed, or individuality 
of the animal. It is especially important to keep the ration uni- 
form, since it has been demonstrated that the nature of the food 
has an important influence, more particularly in regard to the com- 
position of the fat. 

PLAN OF THE INVESTIGATION, 

Eleven animals were selected for the investigation, consisting of 3 
representatives each of the Jersey, Holstein, and Shorthorn breeds, 
and 2 of the Ayrshire breed. These cows were typical specimens 
of the breed — that is to say, neither superior nor inferior producers 
of milk, but about the average. They were all purebred and reg- 
istered. They were kept under much the same conditions as would 
be found in a commercial dairy except in regard to the control of 
the feed of the animals. The ration fed was of uniform composi- 
tion throughout the entire lactation period and was made up as 
follows: 

Choice alfalfa hay 3 parte. 

Grain mixture: 

Com, Sparta ' 

Bran, 1 part -2 parts. 

OatB, 1 part 

This ration supplied the nutrients necessary for milk production in 
about the right proportion. The ratio between the hay and the 
grain was such that the animals would eat the entire ration at all 
times. The amount fed was governed by the needs of the animal. 
The animals all went through the entire lactation period with no ill 
effects resulting from the lack of variety, and in no case was theie 
any serious sickness of any kind. The hay, which was the most 
variable part of the ration, was bou^t in lai^e quantities from the 
same soiurce in order that there might be few changes in its compo- 
sition. The animals were housed at night in the bam for feeding 
and milking and in the daytime were turned outside in a dry lot. 
The date for beginning the taking of samples was 5 days after the 
birth of the calf. The sampling was continued until the production 
of milk declined to the point where in a commercial dairy the cow 
would not be milked longer. A more detailed account of the plan 
of the investigation is found in Bulletin 155, previously mentioned. 

METHOD OF SAMPLING AND PREPARATION OF SAMPLES FOR 

ANALYSIS. 

The milk was weighed immediately after milking and mixed by 
pouring from one pail to another. A sample consisting of about 1 
liter placed in a glass jar bearing the number of the cow and marked 



BESULTS OF THE EXPERIMENTS. 9 

with the amount of milk produced was delivered at the laboratory. 
A certain number of cubic centimeters per pound of milk produced 
was then measured out and placed in a closed receptacle. In this 
manner a composite sample was prepared representing the produc- 
tion of that particular cow for 1 week. The milk was preserved by 
the addition of formalin. At the end of the week the composite 
sample was thoroughly mixed and a subsample consisting of about 
300 c. c. taken for analysis. The remainder of the composite sam- 
ple was heated to the proper temperature and the cream separated 
with a hand-power separator. The cream so obtained was churned 
by shaking in a glass jar, and the butter resulting was melted on a 
steam bath. The methods of sampling and analysis have been 
described in detail in Bulletin 155; it is sufficient to say that the 
methods of analysis followed were those of the Association of Offi- 
cial Agricultural Chemists wherever possible. 

THE TRUE AVERAGE PER CENT. 

In many cases in reporting analyses of milk a simple average 
instead of a true average is given. An average made in this man- 
ner is often misleading. In the case of the constituents of the milk 
it generally gives a result somewhat high, since milk becomes richer 
as it decreases in amount toward the end of the lactation period. 
Unless otherwise stated the averages given in this publication rep- 
resent true averages. The average per cent of fat for the lactation 
period, for example, is found by dividing the total milk into the 
total fat produced. 

RESULTS OF THE EXPERIMENTS. 

Table 1 gives the data concerning the cows used in this investi- 
gation. Under the heading ** Period samples were taken" is shown 
the periods covered by the samples taken for analysis. 

Table 1. — Data concerning the cows used. 



Breed. 



Jeney.... 

Do.... 

Do. . . . 
Aynhire. 

Do.... 
Holstein. 

Do.... 

Do.... 
Shorthorn 

Do.... 

Do.... 



No. 

of 

oow 



4 

90 
118 
800 
301 
205 
206 
200 
400 
402 
403 



Age. 



6 10 
8 1 
11 
3 
4 
5 
6 
3 

4 4 
4 11 
6 



Date of 

calving. 



Nov. 

Jan. 

Sept. 

Dec. 

Sept. 

July 

May 

July 

Sept. 

Oct. 

Feb. 



13,1006 
1,1007 
27,1006 
28,1007 
27,1007 
17,1007 
31,1007 
20,1007 
80,1007 
13,1007 
11,1908 



Date of 
breeding. 



Dec. 30,1006 
Mar. 23,1907 

Not bred 

Feb. 23, 1908 
Mar. 16,1908 
Dec. 1,1907 
Sept. 28, 1907 
Nov. 18, 1907 
Jan. 25,1908 
Dec. 21,1907 
July 7,1908 



Period samples wore taken. 



Nov. 24, 1907, to Sept. 7, 1908. 
Jan. 5, 1907, to Nov. 30, 1907. . 
Oct. 6, 1906, to Oct. 26, 1907... 
Dec. 29. 1907, to Oct. 3, 1908. . . 
Sept. 29, 1907, to Sept. 18, 1908 
July 20, 1907, to Aug. 8, 1908. . 
June 1, 1907, to Apr. 4, 1908. . . 
July 20, 1907, to July 4, 1908. . . 
Oct. 5, 1907, to Aug. 1, 1908. . . 
Oct. 19, 1907, to JvQy 18, 1908. . 
Feb. 15, 1908, to Dec. 19, 1908. 



•To- 
tal 

yield 
of 

milk. 



LbB 

5.429 

6,115 

5,733 

6,276 

6,382 

8,684 

o, 994 

8,814 

6.172 

4,440 

6,530 



Av- 
erage 
fat 
con- 
tent. 



P.ct. 
4.87 
4.64 
5.36 
3.51 



To- 
tal 
yield 
of 
fat. 



Lbt, 
264.45 
284.04 
307.45 
220.34 
3.86 245.64 
3.241280.76 
2.03,263.66 
3.02273.34 
3.891201.37 
4.13183.5? 
3.36 220.62 



10 



INFLUENCE OF BBEED AND INDIVIDUAUTY ON MILK. 



TOTAL SOLIDS. 

The determinations for total solids were made by using the Bab- 
cock asbestos method. The figures given are in each case an average 
of the determinations for 4 weekly composite samples. These are 
simple averages. The averages given for the lactation period of the 
animal and for the breeds are true averages. 

Table 2 gives the percentage of total solids for each of the 11 ani- 
mals used in the investigation by 4-week periods, the average for 
each animal for the period of lactation, and the average by breeds. 
The results correspond closely with those usually given for the breeds 
included. In Table 3 is given a compilation of analyses reported by 
several experiment stations in this country. The figures used 
include only those that represent purebred animals of the respective 
breeds, and where an entire period of lactation is involved. The 
data included in the column headed ** Other American experiment 
stations" include all in print coining under the above conditions. 
A portion of this data was taken presumably by calculation from the 
specific gravity and the fat. Since these animals, owned by various 
experiment stations, represent a variety of conditions, it is believed 
that the average figure given, which includes all the data of such 
kind available up to the present, is reasonably accurate. 

Table 4 gives the composition of the total solids in percentage of 
fat, protein, and sugar. The ash is not included, since it was lacking 
in some of the data, and furthermore, the amount of ash is so uniform 
with the different breeds and different individuals that no marked 
variations were found. The animals supplying the data from the 
New Jersey and New York experiment stations are the same as in 
Table 3. 

Table 2. — Average percentage of total solids far each cow, arid breed average, by 4'Vfeei 

periods. 





Jerseys. 


Ayrshires. 


Four-week period No. 

• 


No. 4. 


No. 99. 


No. 118. 


Average 

for 
Jerseys. 


No. 300. 


No. 301. 


Average 

for Ayr- 

ahirea. 


1 


1 

Per cent. 
14.13 


Per cent. 


Per cent. 


Percent. 
14.13 
13.58 
13.92 
13.64 
13.60 
14.07 
14.02 
14.06 
13.76 
14.43 
14.88 
15.58 
16.10 
17.16 


Percent. 
13.07 
12.27 
12.14 
11.81 
11.66 
11.35 
11.38 
13.15 
13.56 
13.85 


Percent. 
13.20 
12.50 
12.67 
12.64 
13.09 
13.86 
13.68 
13.64 
13.49 
11.78 
13.56 
13.04 
13.37 


Percent, 
18.13 


2 


13.09 
13.30 
13.15 
12.92 
12.76 
13.04 
12.81 
13.35 
14.27 
15.15 
10.08 


14.06 
14.55 


12.39 


3 




13.36 


4 


14.14 
14.28 
14.15 
13.87 
13.77 
13.63 
14.57 


13.33 


5 




13.38 


6 


15.30 
15.16 
15.61 
14.79 
14.45 
14.42 
15.06 
16.10 
17.16 


13.11 


7 


13.01 


8 


13.39 


9 


13.53 


10.... 


13.81 


11...: 


13.55 


12 






18.04 


13 






18.37 


14 






















True average of total solids . 


14 09 


13.34 


15.02 


14.09 


12.08 


12.71 


13.41 



BESULTS OF THE EXPEBIMENTS. 



11 



Table 2. — Average percentage of total solids for each cow, and breed average, by 4'ireek 

periods — Con tinued . 





Holsteins. 




Shorthorns. 




Four-week period No. 


No. 206. 


No. 200. 


No. 209. 


Average 

for 
Holsteins. 


No. 400. 


No. 402. 


No. 403. 


Average 
for Short- 
horns. 


1 


Peret. 
11.74 
11.58 
11.70 
11.95 
12.11 
11.77 
11.98 
12.16 
11.95 
12.12 
12.20 
12.50 
13.04 
13.42 


Peret. 
10.95 
10.10 
10.18 
10.27 
10.54 
10.73 
10.75 

laso 

11.01 
11.90 
13.30 


Peret. 
11.24 
10.23 
10.63 
11.07 
11.15 
10.96 
11.20 
11.23 
11.58 
12.58 
12.99 
13.51 
14.52 


Per cent. 
11.31 
10.64 
10.84 
11.10 
11.27 
11.15 
11.31 
11.39 
11.51 
12.20 
12.83 
13.01 
13.78 
13.42 


Peret. 
13.71 
13.29 
13.05 
12.48 
13.06 
13.05 
12.96 
13.08 
13.03 
12.43 
12.84 


Peret. 
13.74 
13.29 
13.07 
13.07 
13.16 
12.97 
13.02 
12.93 
13.81 
13.94 


Peret. 
12.85 
12.16 
11.75 
11.56 
11.56 
11.65 
12.77 
12.52 
12.38 
12.90 
13.19 


Percent, 
13.43 


2 


12.91 


3 


12.62 


4 


12.37 


5 


12.59 


6 


13.56 


7 


12.92 


8 


12.84 


9 


13.07 


10 


13.09 


11 


13.02 


12 




13 










14 
























True average of total solids. 


12.12 


10.73 


11.35 


11.38 


13.03 


13.01 


12. 17 


12.09 



Tablb 3. — Comparison of total solids in this investigation with results reported by 

American experiment stations. 





This investiga- 
tion. 


New Jersey Ex- 
periment Sta- 
tion.i 


New York Ex- 
periment Sta- 
tion.* 


Other American 
experiment sta- 
tions. 


General average. 


Breed. 


Num- 
ber of 
ani- 
mals. 


Average 

total 

solids. 


Num- 
ber of 
ani- 
mals. 


Average 

total 

solids. 


Num- 
ber of 
ani- 
mals. 


Average 

total 

soUds. 


Num- 
ber of 
ani- 
mals. 


Average 

toUl 

solids. 

Percent, 
14.90 
14.20 
12.98 
12.29 


Num- 
ber of 
ani- 
mals. 


Average 

toUl 

solids. 


Jerseys 

Quenueys. 


3 


Percent. 
14.09 


3 
3 
3 
8 
3 


Percent. 
14.34 
14.48 
12.70 
12.12 
12.45 


3 
2 
4 
2 


Percent. 
15.5 
14.8 
12.8 
12.2 


29 
6 

17 
9 


38 
11 
26 
17 



Per cent. 
14.70 
14.49 


Ayrshire.. 
Holstein.. 
Shorthorns 


2 
3 
3 


12.41 
11.38 
12.69 


12.72 
12.00 
12.57 















1 Neilson, James. Experiments with different breeds of dairy cows. New Jersey Agricultural Experi- 
ment Station, Bulletin 77. New Brunswick, Dec., 1890. 

* New York Agricultural Experiment Station, Tenth, Eleventh, and Twelfth Annual Reports. Geneva, 
1891, 1892, 1883. 

Table 4. — Average composition of the total solids in milk of dairy cattle, as reported by 

American experiment stations. 



Breed. 



jeKBey . •..••■ 
Guernsey.... 

Ayishire 

Holstein 

Shorthorn... 



Fat 



New 
Jer- 
sey. 



P.et. 
33.3 
34.7 
29.1 
29.1 
29.3 



New 
York. 



P.et. 
36.4 
85.1 
37.3 
28.0 



Mis- 
soivi. 



P.et. 
35.1 



29.6 
27.1 
29.4 



Aver- 
age. 



P.et. 
34.9 
34.9 
28.7 
28.1 
29.3 



Protein. 



New 
Jer- 
sey. 



New 
York. 



P.et. 
27.6 
27.1 
27.4 
27.1 
28.3 



P.et. 
25.4 
24.7 
26.3 
27.4 



Mis- 
souri. 



P.et. 
25.8 



26.1 
28.1 
26.0 



Aver- 
age. 



P.et. 
26.3 
25.9 
26.6 
27.5 
26.4 



Sugar. 



New 
Jer- 
sey. 



P.et. 
3d. 8 
33.3 
38.1 
38.7 
38.6 



New 
York. 



P.et. 
33.4 
35.0 
40.8 
39.1 



Mis- 
souri. 



P.et. 
34.5 



89.6 
37.3 
39.3 



Aver- 
age. 



P.et, 
33.9 
34.2 
39.5 
38.4 
38.9 



The fat represents from 28 to 35 per cent of the total solids, varying 
especially with the breed and to some extent with the individual. 
The totd solids produced by the Jersey and Guernsey breeds contain, 



12 



INFLUENCE OF BBEED AND INDIVIDUALITY ON MILK. 



on an average, 34.9 per cent of fat, which is relatively high as com- 
pared with the Holstein, Ayrshire, or Shorthorn breeds. Among the 
breeds included in these data the Holstein, with an average of 28.1 
per cent, has the lowest proportion of fat, while the Shorthorn ranks 
next. The rule is that those animals having a higher per cent of fat 
in the milk also have a relatively larger proportion of fat in the solids. 
The individual animals show some variations, but on the whole they 
follow the characteristics of their breed quite closely. The per cent 
of fat in the total solids produced by the 3 Jerseys used in this inves- 
tigation varied from 34.6 to 35.7, the 3 Holsteins from 26.7 to 27.3, 
while the 3 Shorthorns varied from 27.7 to 31.7. The individual 
variation has to be taken into account in connection with the total 
solids, but is of less importance than is the variation due to breed. 

FAT. 

Table 5 gives the percentage of fat in the nulk of the 11 animals 
represented in the investigation, expressed in the same maimer as 
the total solids. The well-known facts regarding the relative compo- 
sition of the milk for the 4 breeds used is brought out in these data. 

Table 6 gives. the average percentage of fat in the milk of animals 
used in investigations at the New Jersey and New YoA experiment 
stations; also a compilation showing the average per cent of fat for 
all registered animals of the respective breeds, the records of which 
have been published by American experiment stations. This table 
includes only data relating to purebred animals and where it is possi- 
ble to obtain a true average per cent of fat for the entire period of 
lactation. It is believed that the summary, representing as it does a 
large number of animals in different States under somewhat compar- 
able conditions, gives a reliable average as to the fat content of the 
milk of the breeds represented. 

Table 5. — Average percentage of fat for each coWy and breed average^ by i-week periods. 







Jerseys. 






Ayrshires. 


Four-week period No. 


No. 4. 


No. 99. 


No. 118. 


Avera^ 

for 
Jerseys. 


No. 300. 


No. 301. 


Average 
for Ayr- 
shires. 


1 


Percent. 
6.17 
4.63 
5.07 
4.85 
4.81 
5.00 
4.73 
4.51 
4.73 
5.18 


Percent. 
5.22 
4.79 
4.43 
4.40 
4.33 
4.22 
4.36 
4.18 
4.63 
4.98 
5.62 
6.07 


PereejU. 


PercenL 
5.20 
4.91 
5.02 
4.79 
4.88 
4.98 
4.93 
4.83 
4.84 
4.88 
5.23 
5.68 
5.48 
6.47 


Percent. 
4.01 
3.61 
3.38 
3.36 
8.32 
3.26 
3.30 
3.53 
3.74 
4.52 


Percent. 
3.87 
3.74 
3.81 
3.81 
4.08 
3.78 
3.95 
3.94 
3.67 
3.58 
4.92 
3.96 
4.18 


Percent. 
3 97 


2 


5.31 
5.55 
6.11 
5.51 
5.71 
5.69 
5.80 
5.17 
4.47 
4.83 
5.28 
5.48 
6.47 


3.68 


3 


3 60 


4 


S 59 


6 


3 70 


6 


3 52 


7 


3.63 


8 


3 74 


9 


8 71 


10 

11 


4.06 
4 92 


12 




8 96 


13 




4.18 


14 






















True average of total fat. . 


4.87 


4.64 


5.36 


4.95 


3.51 


3.86 


3.68 



' BESULTS OF THE EXPBBIMEKT8. 



13 



Table 5. — Average percentage of fat for each otwo, and breed average, by 4'weeh periode — 

Continued. 



• 




Holsteins. 






Shorthorns. 


rour-week period No. 


No. 206. 


No. 206. 


No. 209. 


Average 

for 
Holsteins. 


No. 400. 


No. 402. 


No. 403. 


Average 
for Short- 
horns. 


1 


P.et. 
3.24 
3.14 
3.02 
3.25 
3.29 
3.06 
3.26 
3.25 
3.15 
3.31 
3.31 
3.49 
3.68 
3.68 


P.ct. 
3.07 
2.88 
2.68 
2.84 
2.80 
3.06 
2.88 
3.00 
8.00 
3.09 
3.40 


P.ct. 
8.12 
2.60 
2.74 
3.24 
8.14 
2.81 
2.94 
3.01 
3.01 
3.52 
3.46 
3.90 
6.28 


Per cent. 
3.14 
2.87 
2.78 
3.11 
3.11 
2.96 
3.03 
3.09 
3.06 
3.31 
3.30 
3.09 
4.48 
3.68 


P.cf. 
4.12 
4.09 
3.99 
3.66 
3.70 
3.69 
3.86 
3.73 
4.05 
4.16 
4.17 


P.ct, 
4.66 
4.17 
3.97 
3.80 
3.84 
3.92 
3.98 
3.90 
4,67 
4.42 


P.ct. 
3.68 
3.38 
3.18 
3.16 
3.14 
3.13 
3.23 
3.66 
3.85 
4.00 
4.06 


Percent. 
4.08 


2 


3.88 


3::::r:::::::::::::::::::::::::: 


3.71 


4 


3.64 


5 


3.66 


6 


3.58 


7 


3.69 


8 


3.73 


9 


4.19 


10 


4.19 


11 


4.U 


12 




13 










14 
























True average of total lat... 


3.23 


2.03 


3.10 


3.09 


3.89 


4.13 


8.37 


3.73 



Tablb 6. — Average percentage cffat in milk qf dairy cattle, at reported by American 

experiment stations. 





New Jersey. 


New York. 


Missouri. 


All American ex- 
periment stations. 


Breed. 


Number 

of 
ftTilmals. 


Average 
fat 


Number 

of 
animals. 


Average 
fat. 


Number 

of 
animals. 


Average 
fat 


Number 

of 
animals. 


Average 


Jersev 


3 
3 
3 
3 
3 


Percent. 

4.78 
6.02 
3.68 
8.51 
3.66 


3 
2 

4 
2 


Percent. 
5.60 
5.16 
3.67 
3.28 


3 


Percent. 
4.'&6 


163 
21 
24 
83 
40 
9 


Percent. 
6.14 


Gnonsey 


4.98 


AyT?lhirfi--.r. T -.r- 


2 
3 
3 


3.68 
3.09 
3.73 


3. 86 


Hblstein 


3.46 


Shorthorn. 


3.63 


Red Poll 






4.03 



















It is a well-known fact that individuals within a breed vary consid- 
erably in the percentage of fat. The data here given are too limited 
to contribute much of value on this point. While by far the greater 
number of individuals within the breed will come close to the average 
for that breed, a comparatively few vary widely. It is characteristic 
of the breeds having the higher percentage of fat to show the greater 
individual variations. The percentage of fat secured during a lacta- 
tion period may also be influenced to some extent by the time of the 
year in which the milking period began.^ On the average the milk 
produced during the fall and early winter has a higher percentage of 
fat than that produced by the same animal in the early spring and 
summer. For this reason the cow that is fresh in the fall and pro- 
duces the largest quantity of milk during the cool weather will have 
a higher average test for the year than will be the case if she freshens 
in the spring and produces the maximum yield duriug the period of 
warm weather. 

"■ -nil. - ■ ■ ■ -- ^ 

1 EcUes, C. H. Jahresseitliche Schwankungen des prozentischen Fettgehaltes in Kuhmilk. Milch- 
wirtschaftlicfaes Zentralblatt, vol. 5, no. 11, p. 488-602. Leipzig, Nov. 1909. 



14 



INFLUENCE OF BREED AND INDIYIDUAUTT ON MILK. 



TOTAL PROTEIN. 

Table 7 gives the percentage of total nitrogen as protein for each 
individual and the average for each breed. The .totals are also cal- 
culated as protein by using the factor 6.38. The results show a 
decided influence due to the breed of the animals, the Jersey having 
a uniformly higher percentage of protein than the others. The Hoi- 
steins are the lowest, while the Shorthorns and Ayrshires range 
between the Holsteins and Jerseys. The marked influence exerted 
by the stage of lactation upon the proportion of this constitutent 
present can be seen from the data given and has been shown in a 
previous publication.^ 

Table 8 is a compilation from the same sources as used in previous 
tables showing the average percentage of protein in the milk>.of 5 
breeds. It will be noted that the figiu*es obtained at the Missouri 
Experiment Station for Holsteins, Jerseys, and Ayrshires are some- 
what lower than those obtained at the New Jersey and New York 
stations, while the figure for the Shorthorns is slightly above. There 
is some variation with the individuals regarding the amount of this 
constituent secreted, as is the case with other constituents of the 
milk. The individuals and breeds having the higher percentage of 
fat have at the same time the higher percentage of protein. The 
same animals also have a higher ratio of fat to protein. With the 
11 cows used in our investigation, for each pound of protein there 
was found in the milk of the Jerseys 1.36 pounds of fat, in the Ayr- 
shires 1.13, in the Shorthorns 1.10, and in the Holsteins 1.05. While 
an individual or a breed that produces milk with a high percentage 
of fat is certain to have a high percentage of protein as well, the pro- 
tein and the fat do not increase in the same proportion. 

Tablb 7. — Average total nitrogen for each eoWj and breed average, &y A-wetk periodic and 
average total niirogen and protein for the whole ladalvm period. 





Four-week period No. 


Jerseys. 


Ajrnhlres. 




No. 4. 


No. 99. 


No. 118. 


Average 

for 
Jerseys. 


No. 800. 


No. 301. 


Avenge 

for Ayr- 

shlree. 


1 


Percent. 
0.52 
.63 
.57 
.61 
.60 
.59 
.59 
.67 
.62 
.66 


Percent, 
0.61 
.51 
.51 
.48 
.49 
.49 
.48 
.60 
.52 
.56 
.62 
.66 


Percent. 


Percent, 

0.52 

.52 

.65 

.55 
.58 
.58 
.58 
.57 
.59 
.62 
.63 
.68 
.75 
.77 


Percent. 
0.53 
.47 
.48 
.47 
.46 
.47 
.46 
.49 
.67 
.67 


Percent. 
0.56 
.50 
.48 
.51 
. .51 
.53 
.51 
.50 
.53 
.53 
.53 
.67 
.65 


Percent. 
0.54 


2 


0.51 
.56 
.54 
.65 
.65 
.67 
.64 
.64 
.64 
, .66 
.70 
.75 
.77 


.48 


3 


.48 


4 


.40 


6 


.40 


6 


.60 


7 


.40 


8 


.50 


9 


.55 


10 


.60 


11 


.68 


12 






•% 


13.. 








]4 1 












True average of total 
nitrogen 














.58 
3.70 

i 


.61 
3.27 


.62 
3.97 


.67 
3.64 


.49 
3.11 


.52 
3.38 


.51 




True average of total 
protein 


3.25 









1 Bulletin 155, Bureau of Animal Industry, U. S. Department of Agriculture. Washington, 1912. 



BESULT8 OF THE EXPERIMENTS. 



15 



Tablb 7. — Avetaae total nittogenfof eadi cowy trnd breed average j by 4^wuh periodSy and 
avenge total nitrogen and protein for the whole lactation period — GontiDued. 





FMr-week period No. 


Holsteins. 


Shortbonis. 




No. 205. 


No. 206. 


No. 209. 


Ayeiage 

for 
Holsteins. 


No. 400. 


No. 402. 


No. 403. 


.Averaget 

for Sbotr- 

homs. 


1.. 


• 


P.ct. 
0.49 
.43 
.44 
.44 
.45 
.45 
.45 
.44 
.48 
.48 
.51 
.55 
.50 
.65 


P.ct. 
0.44 
.38 
.37 
.39 
.42 
.42 
.41 
.43 
.44 
.51 
.71 


P.rt. 
0.50 
.45 
.45 
.47 
.45 
.46 
.50 
.40 
.52 
.60 
.65 
.73 
.71 


P.ct. 
0.48 
.42 

.42 
.43 
.44 
.44 
.45 
.45 
.48 
.53 
.62 
.64 
.65 
.65 


P.ct. 
a54 
.51 
.46 
.48 
.53 
.54 
.56 
.56 
.58 
.60 
.50 


P.cf. 
0.53 
.52 
.51 
.54 
.55 
.55 
.55 
.57 
.63 
.70 


P.ct. 
0.52 
.49 
.47 
.47 
.49 
.51 
.53 
..57 
.58 
.60 
.64 


P.ct. 
0.53 


2 


.51 


3 


.48 


4 


• 50 


5 


.52 


6 •. 


.53 


7 


.55 


8 


.57 
•W 
•63 
•61 


9 


10 


11 


12 


IS 










14 - 












True average of totrf 
nitrofcen 












• • 




.47 
8.00 


.42 
2.70 


.50 
8.21 


.46 
2.93 


.58 
3.40 


.55 
3.49 


.51 
3.28 


•53 
3.38 




True avwagB of total 
pcotain 







Tablb 8. — Average percentage of total protein in milk of dairy caUlCy ae reported by 

American experiment etatione. 





New Jersey. 


Now York. 


Missouri. 


Average. 


Breed. 


Number 
of 


Average 
protein. 


Number 

of 
anlmah. 


Average 
protein. 


Number 

of 
animals. 


Average 
protein. 


Number 

of 
animals. 


Average 
protein. 


Jersey 


8 
8 
3 
8 
3 


Percent. 
3.96 
3.92 
3.48 
3.28 
3.27 


3 

2 

4 
2 


Pereent. 
3.81 
3.75 
3.29 
8.23 


8 


Percent. 
3.64 


9 
5 
9 


Percent. 
3.80 


Guernsey 


3.84 


Ayrshire 


2 
3 
3 


3.25 
2.93 
3.38 


3.34 


Hxilsteln 


8 3.15 


Shortboni. 


6 


3.32 











CASEIN. 

Table 9 gives the average percentage of protein in the form of 
casein for each individual and for each breed. Much the same range 
of variation is foimd here as is the case with the total protein. The 
percentage of the total protein present as casein was for the Holstein 
milk 80.4, the Jersey 80.7, the Ayrshire 83, and the Shorthorn 83.5. 
No special breed characteristics can be observed in regard to the 
relation of casein to the total protein. The individual variation is 
of some importance, but not so very much. 



16 



INPLUENCB OF BBEBD AND INDIVIDUAUTY OK MILK. 



Table 9.— Average auein^ nitrogen for each cow, and breed average, by 4^week periods^ 
and average eaeein nitrogen and eoMeinjor the vihole laeUUion period. 





Four-week period No. 


Jeraejrs. 


Ayrshlres. 




No. 4. 


No. 99. 


No. 118. 


Average 

for 
Jerseys. 


No. 300. 


No. 301. 


Avefage 
for Ayr- 
shins. 


1.. 




Percent. 
0.44 
.38 
.48 
.40 
.48 
.48 
.47 
.46 
.60 
.62 


PereenL 
0.42 
.41 
.40 
.40 
.40 
.40 
.39 
.40 
.42 
.46 
.61 
.68 


PereenL 


Percent. 
0.43 
.37 
.45 
.44 
.47 
.47 
.47 
.47 
.48 
.49 
.61 
.64 
.61 
.68 


Percent. 
0.44 
.40 
.40 
.38 
.39 

•2 

.39 
.44 

.62 
.69 


PereenL 
0.66 
.60 
.48 
.61 
.61 
.63 
.61 
.60 
.63 
.68 
.63 
.67 
.66 


PereenL 
60 


2.. 




.82 

.48 
.42 
.54 
.52 
.54 
.54 
.61 
.60 
.61 
.66 
.61 
.68 


.46 


8 


44 


4.. 


« 


45 


6 


.46 


6 


46 


7 


.48 


8 


47 


9 


.61 


10 


.60 


11 


.68 


12 




" •••••■••• 


.67 


13 - 


•••••••• 




•66 


14.. 














True averace of casein 
nitrogeD 














.46 
2.93 


.42 
2.65 


.49 
3.13 


.46 
2.93 


.41 
2.62 


.44 
2.81 


.42 




True average of casein 


2.70 





Four-week period No. 


Holstelns. 


Shorthorns. 




No. 206. 


No. 206. 


No. 200. 


Average 

for 
HoUtelns. 


No. 400. 


No. 402. 


No. 403. 


Average 

forflhort- 

hflcns. 


1.. 




PereL 
0.40 
.36 
.34 
.36 
.37 
.38 
.37 
.37 
.38 
.39 
.43 
.45 
.51 
.57 


Peret. 
0.34 
.30 
.29 
.30 
.32 
.33 
.31 
.38 
.36 
.42 
.68 


PereL 
0.39 
.84 
.34 
.36 
.85 
.36 
.39 
.40 
.41 
.49 
.53 
.69 
.68 


Peret. 
0.38 
.83 
.82 
.34 
.35 
.36 
.36 
.87 
.38 
.43 
.51 
.52 
.54 
.57 


PereL 
0.45 
.41 
.38 
.38 
.44 
.44 
.45 
.46 
.45 
.48 
.63 


Peret. 
0.44 
.48 
.42 
.44 
.46 
.44 
.46 
.46 
.68 
.66 


PereL 
0.42 
.88 
.86 
.87 
.87 
.43 
.46 
.47 
.46 
.45 
.48 


PereL 
0.44 


2 


.41 


3 


.39 


4 


.39 


5 


.42 


6 


.44 


7 


.45 


8 


.46 


9 


.48 


10 


.40 


11 


.61 


12 




18 










14. 






• * * 






True avenge of casein 
nitrogen 
















.39 
2.49 


.33 
2.11 


.39 
2.49 


.37 
2.36 


.43 
2.74 


.45 

2.87 


.41 
2.62 


.48 




True avenge of casein 


2.74 



RELATION OF THE CASEIN TO THE PAT. 

The relation between the fat and the casein is of considerable 
interest on account of the possibility it aflFords of calculating the 
casein content from the fat analyses and its relation to methods of 
paying for milk of varying quality to be used for cheese making. 
Van Slyke ^ formulated a rule for estimating the casein, limited in 
its application to milk with fat contents between 3 and 4.5 per cent. 
Shuttleworth ' showed that considerable variations occur with indi- 
vidual cows regarding the relation of fat to casein. 

I Van SlykB, Ludus L. Modem methods of testing milk and milk products. New York, 1907. See 
p. 192. 

* Ontario Agricultural College and Experimental Farm, Twenty-first Annual Report (1895), pp. 19-27. 
Toronto, 1896^ 



BESULTS OF THE EXPERIMENTS. 



17 



Hart * studied the relation between the fat and the casein in the 
milk of 26 cows representing 5 breeds and covering 12 days' time. 
He finds that ''the relation of casein to fat varies among animalg of 
different breeds and among animals of the same breed." His data 
averaged by breeds are as follows: 



Breed. 



Jersey. . . 
Querzuey 
Holstein. 
Ayrahiie. 



Relation 

of fat and 

casein. 



1.72:1 
1.90:1 
1.49:1 
1.44:1 



The following gives the relation of the fat to the casein in the milk 
of each of the 11 cows used in our investigation: 



Breed. 


No. 


Ratio Of 

liftttO 


Jersey 


4 

99 

118 


1.66:1 
1.76:1 
1.71:1 


Do 


Do 


ATeraga for Jerseys 


1.69:1 


Ayrshire 


300 
801 


1.20:1 
1.47:1 


Do 


Average for Ajrrshires. . . . 


1.36:1 


Holstein .-. 


205 
206 
209 


1.30:1 
1.38:1 
1.25:1 


Do 


Do 


Averase for Holstelns. . . . 


1.31:1 


Shorthorn 


400 
402 
403 


1.35:1 
1.44:1 
1.29:1 


Do 


Do 


A veraee for Shorthorns . . . 


1.36:1 







The above statement, representing as it does in each case the 
entire lactation period of the animal fed a uniform ration, gives a 
fair basis from which to study this question. The figures show that 
there is a variation in the ratio between the fat and the casein that is 
dependent upon breed. There is little difference between the 
Holstein, Ayrshire, and Shorthorn breeds, but the Jersey shows a 
much wider ratio than the others. A study of the figures for 
the individual animals shows a reasonably close agreement within 
the breed. The conclusion from our data would be that while there 
is some variation with the individual the variation due to breed is of 
greater importance, and that the breeds that have the highest per- 
centage of fat have the widest ratio between the fat and the casein. 



1 Hart, E. B. Variations in the amount of casein in oow's milk. Journal of the American Chemical 
Society, Yol. 80, No. 2, pp. 281-285. Eastim, Pa., Feb., 1908. 



18 



INFLUENCE OF BREED AND INDIVIDUAUTY ON MILK. 



SUGAR. 

The sugar content was determined by the optical method.* The 
results are found in Table 10. This table shows that the percentage 
of sugar in the milk of the Jersey, Ayrshire, and Shorthorn breeds was 
practically the same, while that in the Holstein was somewhat lower. 

Table 11 gives the average percentage of sugar from the same 
sources as previously used. The average figures show that the 
Holstein breed has a somewhat lower percentage of sugar than the 
other breeds, although the variation is small as compared with that 
of other constituents. It is a well-established fact that, with the 
exception of the ash, sugar is the least subject to variations of the 
milk constituents. Some variation, however, is found with the 
individuals. This is especially noticeable with the Holsteins, where 
one has an average of 5.05 per cent and another 4.25 per cent. The 
sugar composes from 34 to 39 per cent of the total solids, varying in 
this respect with the breed. 

Table 10. — Average percentage of sugar for each cow, and breed average, by 4-v)eeh periods. 





1 


Jerseys. 






Ayishires. 




Fourweek period No. 


No. 4. 


No. 99. 


No. 118. 

• 


Average 

for 
Jeraeys. 


No. 300. 


No. 301. 


Average 
for Ayr- 
shires. 


1 


1 

Per cent. 
4.89 
4.9B 
4.87 
6.28 
6.12 
5.00 
4.39 
4.45 
4.67 
4.60 


Percent. 
4.94 
5.15 
5.17 
5.06 
5.04 
4.50 
4.62 
5.14 
4.62 
5.03 
5.02 
5.61 


Percent. 


Per cent. 
4.92 
4.87 
4.91 
4.97 
4.99 
4.90 
4.70 
4.99 
4.62 
4.79 
4.96 
6.17 
4.46 
5.22 


PereerU. 
5.14 
4.81 
4.64 
4.87 
4.96 
4.57 
4.82 
5.06 
5.13 
4.89 


Percent. 
5.17 
4.72 
5.62 
5.16 
4,77 
4.43 
5.38 
5.13 
4.85 
4.88 
4.89 
5.04 
5.13 


Percent. 
5.16 


2 

3 

4 


4.47 
4.70 
.4.56 
4.83 
5.21 
5.20 
6.40 
4.57 
4.73 
4.90 
4.72 
4.46 
5.22 


4.77 
5.13 
5.02 


6 

6 


4. 87 
4.50 


7 


5.10 


8 


5.11 





4.99 


10 


4.64 


11 


4.89 


12 




5.04 


13 




5.13 


14 




















True total average 


4.85 


4.95 


4.80 


4.87 


4.85 


4.96 


4.90 



Four-week period No. 



Holsteins. 



No. 205. 



1 

2 

3 

4 

6 

6 

7 

8 

9 

10 

11 

12 

13 

14 

True total average 



Perct. 
4.09 
4.98 
4.81 
5.18 
6.42 
6.37 
5.20 
4.76 
5.10 
5.12 
5.13 
5.02 
4.89 
4.81 



5.05 



No. 206, 



Perct. 
4.07 
4.49 
4.44 
4.12 
4.26 
4.04 
4.74 
4.25 
4.09 
3.94 
4.50 



4.26 



No. 209. 



Perct. 
4.40 
4.00 
4.17 
3.95 
4.42 
4.36 
4.16 
3.94 
4.43 
4.62 
4.79 
4.15 
4.30 



4.25 



Average 

for 
Holsteins. 



Perct. 
4.39 
4.49 
4.48 
4.42 
4.70 
4.59 
4.70 
4.32 
4.54 
4.56 
4.81 
4.64 
4.60 
4.81 



4.51 



Shorthorns. 



No. 400. 



Perct. 
5.40 
6.06 
5.44 
5.13 
4.87 
4.95 
5.06 
5.19 
4.66 
4.22 
4.25 



No. 402. 



Perct. 
4.77 
5.32 
5.09 
4.72 
4.55 
5.09 
5.29 
4.73 
4.61 
4.31 



5.04 



No. 403. 



Perct. 
5.21 
5.22 
6.39 
5.00 
4.58 
5.16 
4.98 
6.11 
4.08 
4.17 



Average 
for Short- 
horns. 



4.91 



4.98 



Perct. 
6.13 
5.20 
6.31 
4.95 
4.67 
5.07 
5.11 
5.01 
4.45 
4.23 
4.25 



4.99 



1 OflSdal and provisional methods of analysis. U. S. Department of Agriculture, Bureau of Chemistiy, 
Bulletin 107 (revised). Washington, 1908. See p. 118. 



BESULTS OF THE EXPBBIMEiNTS. 



19 



Tablb 11. — Average percentage ofeiLgar in milk qf dairy eaitle, as reported by American 

experiment stations. 



Breed. 



Jersey 

Guernsey. 
Ayrshire.. 
Holstein.. 
Shorthorn 



New Jersey. 


New York. 


Missouri. 


Average. 


Number 
of 


Average 
sugar. 


Number 

of 
animals. 


Ayerage 
sugar. 


Number 
of 

Animal^, 


Average 
sugar. 


Number 

of 
animals. 


Average 
sugar. 








3 
3 


Percent. 
4.85 
4.80 

4.84 
4.09 
4.80 


3 

a 

4 

2 


Percent. 
5.41 
5.16 
5.33 
5.02 


3 


Per cent. 
4.87 


9 
5 
9 
6 
6 


Percent. 
5.04 
4.98 


3 
3 
3 


2 
3 
3 


4.90 
4.25 
4.99 


5.02 
4.65 
4.89 











THE CHEMICAL AND PHYSICAL CONSTANTS OF THE FAT. 

While the previously published data regarding the constituents of 
milk are extensive, little is in print concerning the chemical and physi- 
cal constants of the fat as influenced by the breed and individuality of 
the anunal, with the exception of the relative size of the fat globules. 
Veith * studied the milk of 3 breeds of cows and concluded that the 
breed does not have any appreciable influence upon the nature of the 
fat. Kirchner' states that the composition of the fat is dependent 
mostly upon the stage of lactation and the food of the animal, but also 
varies to some extent with the individual animal. 

The object of the investigations herein reported, as far as the varia- 
tions due to breed and individuality are concerned, was especially to 
gather data concerning the fat. Since the rations fed the animals was 
uniform in all cases, the variations found can reasonably be attributed 
to the influence of the breed or of the individual. 

RELATIVE SIZE OF THE FAT GliOBULES. 

The determination of the relative size of fat globules was introduced 
by Babcock.' A description of this method of measurement is also 
found in Bulletin 111, Bureau of Animal Industry, United States 
Department of Agriculture. The method is essentially one of com- 
paring the average volumes. It has been observed by several inves- 
tigators that the breed of the animal has a decided influence upon the 
size of the fat globules. Jones ^ found that the milk of the Holstein 
had a much larger proportion of small fat globules, while the Jersey 
and the Guernsey had the lai^est, the Ayrshire standing between. 
Woll ^ gives the following data concerning the size of the fat globules 

1 Vieth, P. ButterfBtt-Untersuchungen nach Reichert-Wollny 's Methode. Milch Zeltung , vol. 18, no. 
28, p. 541-^645. Bremen, July 10, 1889. 

*Klrchner,W. Handbuch der Milchwirtschaft. Berlin, 1896. Seep. 16. 

•New York Agricultural Experiment Station, Fourth Annual Report (1885), p. 293-302. Albany, 1886. 

« Jones, L. R. Study of milk globules. Vermont Agricultural Experiment Station, Fourth Annual 
Report (1890), p. 65-09. Burlington, 1891. 

• Woll, F. W. The fat globules in cows' milk. Wisconsin Agricultural Experiment Station, Eleventh 
Annoal Report (1894), p. 223-239. Madison, 1895. 



20 



INFLUENCE OF BREED AND INDIVIDUALITT ON MILK. 



in the milk of the 3 breeds which were* entered in competition at the 
Columbian Exposition at Chicago in 1893: 



Breed. 


Number 

OfOOWB. 


Relative 

else of 

globules. 


Average 


Jeney 


25 


200 
217 
177 


Jikrofu. 
3.95 
3.58 
3.35 


Guernsey 

Shorthom 


1 25 
24 



Gutzeit^ gives the average diameter of the fat globules in his inves- 
tigation as follows: 

Mkrotu. 

Jersey 3. 60 

Shorthom 2.76 

Holstein 2.58 

Table 12 gives the relative size of the fat globules as determined for 
each of the 1 1 animals used in our investigation and the averages for 
the breeds. This table shows the same results as noted by others, the 
Jersey having by far the largest fat globules, while the Holstein have 
the smallest, the Shorthom standing between the Holstein and the 
Jersey. The comparative size of the fat globules in the milk of these 
4 breeds is illustrated graphically in figure 1. The chief difference 







AYRSHIRE 
jtRSVf SHORTHORN 

Fio. 1.— Relative sixe of the fat globules in tbe milk of dairy cattle. 



HOLSTEIN 



between the size of the fat globules with the different breeds is that 
with the Jersey there is a greater proportion of the larger globules and 
that the milk of the other breeds contains a limited number as large 
as the lai^est in the Jersey milk. The milk of the Holstein breed is 
especially noticeable in containing a large number of small fat globules, 
together with a wide variation in size. 

The table shows that the individuality of the animal has some influ- 
ence upon the size of the fat globules, but it is of less importance than 
the breed characteristic. The milk of an Ayrshire or a Holstein can 
be distinguished from that of a Jersey with considerable certainty by 
the characteristic of the fat globules alone. The Shorthorn, on the 

1 Qutzelt, Erzist. Die Schwankungen der mittleren QrSsse der FettkOgelchen in der Kuhmllch nacfa 
Laktatlon, Futterung und Basse, sowle Ober den physikalischen und chemischen Unterscbied der 
grOssten und kleinsten Fettkfigelcben. Landwirthscbaftllche JahrbQcher, vol. 24, p. 539-667. Berlin, 
1895. Seep. 648. 



BESULTS OF THE EXPEBIMENTS. 



21 



other hand, has fat globules that in many cases are as large as those 
contamed m the milk of the Jersey, although less uniform in size. 

Table 12. — Relative size of fat globules in milk of each cow, and breed average^ by 4-week 

periods. 





Four week period No. 


Jerseys. 


Ayrsblres. 




No. 4. 


No. 99. 


No. 118. 


Average 

for 
Jerseys. 


No. 300. 


No. 301. 


Average 
for Ayr- 
shires. 


1 


363 
423 
370 
229 
267 
267 
235 
299 
318 
228 
167 


558 

339 
325 
274 
264 
349 
370 
367 
270 
209 
263 
315 




460 
381 
371 
461 
296 
326 
302 
333 
306 
232 
257 
2/2 
438 
461' 




235 

163 

148 

135 

115 

133 

93 

80 

75 

129 


232 

189 
142 
156 
165 
178 
163 
151 
146 
114 
146 
93 
110 


234 


2 




176 


3 


417 
879 
358 
373 
301 
334 
335 
259 
342 
229 
438 
461 


145 


4 


145 


5 


140 


6 


156 


7 


128 


8 


116 


9 


111 


10 


122 


11 


146 


12 




03 


13 






110 


14, .- - - 












True ftverase of relative 
siseofglobuliw 














309 


336 


338 


328 


141 


160 


150 










Four-week period No. 


Holsteins. 




Shortbonu. 






No. 206. ] 


No. 206. 


No. 209. 


Average 
for • 
HolsteiUB. 


No. 400. 


No. 402. 


No. 403. 


Avenge 

for Short- 

bonis. 


1 


242 

147 
148 
147 
127 

82 
107 

96 

98 

90 

81 
117 
102 . 
179 . 


253 

269 

124 

157 

134 

156 

132 

110 

96 

74 

79 


321 

139 

136 

138 

104 

89 

96 

99 

106 

79 

63 

76 

118 


272 

186 

136 

147 

122 

109 

112 

102 

99 

81 

74 

97 

110 

179 


442 
503 
317 
246 
250 
277 
231 
197 
214 
179 
194 


566 
561 
394 
274 
280 
282 
271 
214 
213 
193 


357 
303 
213 
183 
134 
141 
146 
147 
203 
175 
128 


456 


2 


486 




306 


4 


234 


6 


221 


6 


217 




210 


8 


186 


9 


210 


10 


182 


11 


161 


12 






13 










14 












True average of relative 
sise of globules 
















127 


164 


IM 


142 


311 


353 


211 


282 





















TBB REICHERT-lfEISSL NUMBER.^ 

The results for the Reichert-Meissl number are given in Table 13. 
The Holsteins show the lowest figure for the number, although the 

1 This and the two succeeding constants of the f^t were determined by official methods, the details of 
which may be found in Bulletin 107 (revised), Bureau of Chemistry, U. S. Department of Agriculture. 
For the benefit of those who may be unfamiliar with the terms the following explanation may be helpful: 
The Reichert-Meissl number is an arbitrary measure of the volatile acids of which butyric is the principal 
one In butterfat. The figures do not show the percentages of the acid, but serve as a means of comparing 
dtflerent faXa with reference to their volatfle constituents. The iodin absorption number indicates rela. 
tively the amount of iodin a fat will absorb. Since the only fotty acid found to exist in butterfitt which 
has the property of absorbing iodin is oleic acid, the iodin absorption number shows relatively the amount 
of this fatty add present, but in common with the Reichert-Meissl number the figures do not represent 
percentages. The saponification number is the number of milligrams of potassium hydroxid required 
to saponify 1 gram of tat. Since the amount of potassium hydroxid required dei)ends upon the molecular 
weight of the tat the saponification number serves as an indicator of the relative percentages of the fatty 
acids of high and low molecular weights present. 



22 



UTFLUENCE OF BBEED AND IKDIVIDUALIXT ON MILK. 



Ayrshires on the average are only 0.5 higher, while the Shorthorns 
and the Jerseys show a somewhat higher figure. The individual 
variations are very marked in the case of Jersey No. 118 with an 
average of 23.28, which is the lowest of the entire number. If the 
data of this individual was not included the average for the Jersey 
would be considerably higher than any of the other breeds. With 
the exception of this individual there is no marked variation that is 
to be attributed to the individuality of the animal. The marked 
variation in the Reichert-Meissl number due to the advance in the 
period of lactation is evident from the table. 

Table 13. — Average Reichert-Meissl number for each cow, and breed average , by 4-week 

periods. 



• 


Jerseys. 




Aynhires. 




Four-week period No. 

• 


No. 4. 


No. 99. 


No. 118. 


1 

Average 

for 
Jeneys. 


No. 300. 


No. 301. 


Average 
tor Ayr- 
shires. 


1 


29.22 
28.72 
28.53 
28.50 
28.96 
29.20 
26.87 
28.63 
25.24 
25.95 


30.16 
28.88 
32.09 
30.95 
27.67 
31.21 
27.03 
27.54 
27.03 
25.83 
24.73 
18.43 


29.54 
23.28 
^.14 
23.69 
23.90 
24.64 
26.66 
23.12 
25.04 
^85 
22.79 
20.22 
14.23 
14.21 


29.64 
26.96 
28.25 
27.71 
26.84 
28.35 
26.83 
29.76 
25 n 
24.88 
23.76 
19 33 
14.23 
14.21 


27.66 
28.95 
27.76 
25.76 
26.83 
25.76 
24.57 
23.87 
23.09 
17.96 


30.59 
27.09 
26.58 
25.13 
24.88 
26.79 
25.59 
26.40 
24.42 
24.36 
18.09 
21.72 
30.67 


29.13 


2 


28.08 


3 


27.17 


4 


25.45 


6 


25.86 


6 


26.28 


7 


25.06 


8 


25.29 


9 

10 


23.76 
21.10 


11 


18.00 


12 






21.72 


13 






30.67 


14 






















True avera^ of Relchert- 
Meissl number 


28.17 


28.69 


23.28 


26.73 


26.34 


25.52 


25.93 







• 


Holsteins. 


Shorthorns. 


Four-week period No. 


No. 206. 


No. 206. 


No. 209. 


Average 

for 
Hotsteins. 


No. 400. 


No. 402. 


No. 403. 


Avenga 

for Short- 

horns. 


1 


26.66 
26.01 
26.33 
27.38 
27.82 
26.92 
28.05 
27.53 
27.86 
26.06 
25.63 
20.39 
12.77 
10.27 


30.15 
29.48 
28.15 
24.58 
27.19 
24.51 
24.28 
23.39 
23.53 
20.76 
17.62 


25.66 
26.84 
25.10 
27.06 
24.82 
24.68 
22.79 
23.47 
24.23 
20.17 
21.32 
30.70 
21.14 


27.49 
27.44 
26.53 
26.34 
26.61 
25.37 
25.04 
24.80 
25.21 
22.33 
21.52 
30.55 
16.96 
10.27 


30.77 
29.31 
25.95 
25.99 
28.58 
26.54 
24.70 
25.99 
24.46 
22.57 
22.25 


30.72 
27.14 
26.69 
25.60 
26.07 
24.12 
23.75 
22.93 
18.39 
16.61 


29.36 
20.67 
26.31 
26.30 
25.69 
26.02 
26.38 
34.53 
28.27 
24.25 
25.51 


30.28 


2 


37.71 


3 


36.32 


4 


25.96 


5 


36.78 


6 


25.56 


7 


34.04 


8 


34.48 


9 


22.04 


10 


21.14 


U 


23.88 


12 




13 










14 
























True average of Reichert- 
Meissl number 


25.81 


26.13 


24.44 


25.46 


26.89 


25.55 


26.29 


26.28 







BSSULT8 OF THE EXPBBIMSI^S. 



28 



IBM TOfOm ABSOBPnON NUMBBB. 

Table 14 giyes the data in regard to the iodin nnmber for each 
individual and for the 4 breeds. It will be observed that with this 
constant there is an evident variation due to breed. The Shorthorn 
and the Holstein show a noticeably higher iodin number than the 
Jersey, while the Ayrehire comes between. The Jersey cow No. 118 
shows an individual variation in this respect, as is the case with the 
Reichert-MeissI number. If the figures on this animal be left out of 
the total the variation with the breeds would be even more marked. 
The variation with the breeds, since it shows practically the same for 
each individual, seems sufficient to warrant the conclusion that there 
is a variation in this constant to be attributed to breed and that the 
Holstein and the Shorthorn may be expected to show the highest 
figures, while the Jersey is at the other extreme. 

Tablb 14. — Average iodin number for each cow, <md breed average , by j^week periodt. 





Jerseys. 




Ayishlres. 




Four-wash period No. 


No. 4. 


No. 99. 


No. 118. 


Average 

for 
Jemys. 


No. 300. 


No. 301. 


Average 
for Ayr- 

abina. 


1 


31.06 
28.04 
29.61 
20l94 
28.84 
28.03 
31.46 
29.76 
32.27 
32.16 


32.68 
29.46 
28.96 
26.76 
20.99 
27.29 
27.93 
27.37 
28.71 
28.80 
27.61 
29.65 


39 31 
36.33 
82.64 
28.69 
81.65 
30.43 
28.67 
38.49 
38.67 
31.43 
31.14 
32.37 
38.48 
36.82 


31.36 
81.28 
80.37 
28.46 
30.13 
28.68 
29.35 
29.87 
81.66 
30.79 
29.38 
30.96 
38.48 
36.82 


32.68 
28.70 
^.60 
31.91 
27.60 
29.61 
36.30 
37.32 
36.28 
37.74 


28.68 
29.91 
30.66 
29.86 
30.98 
30.31 
31.04 
80.64 
32.64 
36.11 
44.11 
30.62 
86.80 


30.63 


2 


29.31 


3 


29.13 


4 


30.88 


6 


29.22 


6 


29.96 


7 


38.17 


8 


33.98 


9 


33.94 


10 


36.48 


U 


44.11 


12 






30.62 


13 






36.80 


14 






















True total overafo 


29^99 


28.87 


32.79 


30.62 


31.14 


32.06 


31.61 





Holsteins. 




Shorthorns. 


l^jDur-weakparlod- No. 


No. 206. 


No. 206. 


No. 209. 


Average 

for 
Holsteins. 


No. 400. 


No. 402. 


No. 403. 


Average 

teRhort- 

nona. 


1 


37.12 
34. JM 
33.23 
31.86 
31.77 
32.64 
32.62 
33.46 
34.07 
36.56 
35.40 
37.68 
42.67 
42.24 


31.00 
30.67 
36.63 
31.70 
31.79 
31.67 
33.14 
84.25 
83.91 
86.27 
36.63 


39.46 
33.32 
32.89 
38.10 
88.63 
84.91 
88.62 

87.01 
89.06 
36.35 
86.60 
89.03 


36.86 
32.81 
83.88 
32.22 
82.36 
33.07 
34.13 
34.48 
35.00 
36.68 
35.76 
37.11 
40.80 
42.24 


80.13 
82.12 
39.06 
31.36 
31.66 
33.31 
35.71 
33.26 
34.28 
36.91 
38.49 


30.76 
30.21 
3L16 
30.42 
82.08 
36.16 
86.13 
36.47 
41.01 
42.19 


33.38 
36.18 
33.19 
38,76 
86.28 
36.67 
34.96 
36.34 
87.32 
36.24 
86.04 


31.42 


2 


36.60 


3 


84.46 


4 


31.84 


6 


83.01 


6 


34.68 


7 


86.26 


8 


86.02 


9 


37.54 


10 


38.11 


11 


36.77 


12 




13 










14 
























Tnia total avenge 


84.40 


82.68 


86.48 


34.20 


34.06 


34.00 


34.72 


34.36 



24 



INFLUENCE OF BBEED AND INDIVIDUAUTy ON MILK. 



THE SAPONIFICATION OR KOSTTSTOBFER NUMBER. 

The data regarding this constant are found in Table 15. The varia- 
tions that may be attributed to breed are comparatively small. The 
Holsteins show a number 1.5 higher than the Shorthorns. This dif- 
ference, while comparatively small, seems to indicate at least some 
tendency for a variation between these two breeds. With this excep- 
tion no special variation can be observed that may be attributed 
safely to the influence of the breed. No marked individual varia- 
tions are observed, with the exception of Jersey cow No. 118, which 
shows individual variations in this as well as in the other constants. 
A high iodin number is usually associated with a low Reichert-Meissl 
number and a low saponification number. The data of cow No. 118 
follow this rule. The variations, however, are not sufficient to justify 
any special emphasis being placed upon either breed or individuality 
as a factor in causing variations in the saponification number. 

Table 15. — Average saponification number for each cow, and breed average ^ by ^-week 

periods. 



■ 


Jerseys. 


Ayrshires. 


I our-week period No. 


No. 4. 


No. 99. 


No. lis. 


Average 

for 
Jerseys. 


No. 300. 


No. 301. 


Average 
for Ayr- 
shires. 


1 


231.1 
233.1 
232.9 
229.1 
230.7 
229.0 
227.8 
229.4 
234.4 
235.9 


23a6 
232.1 
229.6 
232.3 
227.7 
231.7 
227.3 
239.8 
234.3 
231.4 
229.4 
219.6 


22&6 
224.7 

229.6 
229.0 
28a2 
226.6 
229.4 
224.8 
226.1 
227.6 
237.0 
223.9 
219.5 
219.1 


28ai 

229.9 
2S0.7 
230.1 
229.5 
229.1 
228.2 
231.3 
231.3 
231.6 
233.2 
221.8 
219 5 
219.1 


232.6 
^3a7 
"S2.3 
224.8 
229.2 
23ai 
224.5 
222.0 
223.9 
217.2 


236.9 
234.1 
232.0 
230.4 
227.5 
229.7 
219.6 
228.3 
228.4 
224.3 
216.2 
218.7 
221.8 


234.7 


2 


232.4 


3 


232.1 


4 


227.6 


6 


228.4 


6 


229.9 


7 


m 


8 


225l1 


9 


226.1 


10 


220.8 


11 


216.2 


12 






218.7 


13 






221.3 


14 






















Trae total average 


231.3 


228.6 


227.2 


228w9 


228.4 


227.9 


228.2 




Holsteins. 

1 


Shortboms. 


Four-week period No. 


No. 205. 


Mo. 206. 


No. 209. 


Average 

for 
Holsteins. 


No. 400. 


No. 402. 


No. 408. 


Average 
for Short- 
boms. 


1 

2 

3 

4 


1 

' 242.2 
229.3 

, 229.0 
232.9 
230.8 
228.7 
228.1 
227.0 
225.0 
223.9 
226.3 

220.8 . 
210.1 . 

206.9 . 


230.7 
228.3 
242.4 
233.7 
232.4 
231.2 
229.7 
226.6 
224.4 
219.9 
216.4 


237.2 
230.6 
231.6 
230.8 
228.3 
229.0 
224.0 
222.4 
222.0 
219.2 
222.0 
23a3 
21&3 


233.4 
229.4 
234.3 
232.8 
230.6 
229.6 
227.3 
226.0 
223.8 
221.0 
221.6 
226.5 
212.7 
205.9 


232.3 
231.7 
224.2 

23ao 

229.4 
227.2 
223.0 
226.5 
224.9 
220.5 
216.8 


234.3 
233.9 
229.8 

22:1 

228.3 
224.3 
223.7 
222.7 
215.8 
211.5 


234.3 
226.4 
228.1 
229.9 
226.4 
2301 
224.6 
225.1 
223.8 
226.4 
226.6 


233.6 

a3a8 

227.4 
227.6 


5 


228.0 





227.2 


7 


224.1 


8 


224.8 


9 


221.5 


10 


219.6 


11 


221.7 


12 






13 










14 
























Trae total averase 


228.2 

1 


23ai 


220.1 


2». 1 


227-6 


226.9 


227.9 


227.6 






1 




1 




1 




1 





BBSTILTS OF THE EXPEBIMENTS. 



25 



THB MSLITKO POINT OF THB FAT. 



The melting point was determined according to Wiley's method. 
An examination of the data given in Table 16 shows a close agreement 
in the melting point for all of the animals. Apparently there is no 
variation in the melting point that could reasonably be attributed 
either to the breed or to the individuality of the animal supplying 
the samples. A marked variation is noticeable due to the advance 
in lactation period, but this is regardless of the individual or breed. 

Table 17 gives a summary for comparison of the constants of the 
fat for the four breeds. 

Tabi«k 16. — Average melting point of ihefaXfor each cow, and breed average^ by 4-week 

'periods. 





, Jerseys. 




Ayrshires. 




Four-week period No. 


No. 4. 


No. 99. 


No. 118. 


Average 

for 
Jerseys. 


No. 300. 


No. 301. 


Average 
for Ayr- 
shires. 


1 


•c. 

32.36 
32.63 
33.89 
32.25 
33.30 
33.44 
32.94 
33.24 
83.08 
32.97 


•a 

24.94 
33.24 
33.36 
34.63 
33.78 
34.08 
84.07 
34.88 
84.64 
33.81 
34.88 
34.36 


26.62 
32.66 
33.31 
83.31 
83.80 
33.40 
33.92 
33.66 
33.39 
33.59 
33.81 
33.68 
33.46 
33.60 


•a 

27.97 
32.84 
83.36 
33.36 
33.63 
33.64 
33.64 
33.74 
33.69 
33.46 
34.35 
34.02 
33.46 
33.60 


34.80 
33.39 
33.45 
33.64 
33.74 
33.87 
33.83 
33.30 
33.30 
34.04 


•c. 

32.07 
33.21 
32.61 
32.80 
33.86 
32.98 
33.98 
33.65 
33.33 
33.10 
34.36 
33.23 
33.28 


34.44 


2. 


33.30 


3 


33.03 


4 


33.17 


5 


33.79 


6 


33.43 


7 


33.90 


8 


33.43 


9 


33.32 


10 


33.67 


11 


34.36 


12 






33.23 


13 






33.28 


14 


















True total average 


32.91 


. 32.95 


32.99 


32.95 


33.75 


33.20 


88.47 







Holstelns. 




Shorthorns. 


Four-week period No. 


No. 205. 


No. 206. 


No. 209. 


Average 

for 
Holstelns. 


No. 400. 


No. 402. 


No. 403. 


Average 
for Short- 
horns. 


1 


33.41 
32.67 
33.39 
33.76 
33.02 
32.93 
32.88 
32.98 
33.26 
33.09 
33.01 
82.54 
41.80 
48.34 


32.96 
33.52 
31.94 
32.06 
32.47 
32.47 
32.64 
83.13 
32.81 
32.92 
38.80 


•c. 

32.58 
32.16 
32.06 
31.84 
33.04 
31.60 
32.30 
32.78 
32.85 
33.82 
33.15 
35.45 
37.39 


•a 

32.98 
32.78 
32.46 
32.56 
32.84 
32.36 
32.61 
32.96 
32.97 
33.28 
34.99 
33.99 
39.59 
48.38 


33.91 
82.99 
31.61 
33.15 
33.01 
33.88 
33.63 
34.13 
34.21 
85.40 
36.49 


32.69 
32.79 
33.20 
33.09 
32.96 
33.99 
33.76 
33.79 
34.65 
36.31 


32.70 
33.32 
32.70 
32.60 
33.15 
82.98 
32.54 
32.66 
83.14 
33.28 
32.83 


33.10 


2 


33.08 


3 


32.50 


4 


32.05 


5 


33.04 


6 


32.63 


7 


33.31 


8 


33.52 


9 


34.00 


10. 


34.99 


11 : 


34.66 


12 




13 :.:.:...; 










14. 






















True total average 


33.76 


32.87 


32.02 


32.88 


33. .56 


33.37 


32.89 


33.23 



26 INFLUENCE OF BBEED AND INDIVIDUALITY ON MILK. 

Table 11, --Average ekeimuxd and pkjfmad etmitanturf the fat by breeds. 



BuBsd. 


Relative 
globules. 


Todfn 
nondMr; 


Saponifl- 

ctttifltt 

number. 


Rekbert- 
number. 


lleUinff 
pone 


Jcnev 


328 
ISO 
142 
282 


30.52 
31.61 
34.20 
34.38 


228.9 
228.2 
229.1 
227.6 


26.73 
21.98 
25. 4« 
26.21 


32.96 


Y*°j;.V. 


31:47 


Hbtoteln 


32.88 


^Vwrtbsni .•••.■•«.. .................•■••• 


33.23 







SUMMARY AND CONCLUSIOIfS. 

1. The data presented show the influence of the breed and the 
individual upon the composition of the milk and upon the constants 
of the fat as evidenced by 11 cows, including 3 each of the Jersey, 
Holstein, and Shorthorn breeds, and 2 of the Ayrshire breed. These 
cows were kept upon a uniform ration and the samples represent an 
entire lactation period for each. A compilation is also given which 
includes all complete analyses of the milk of purebred animals for 
entire lactation periods published up to the present by American 
experiment stations. 

2. The average percentage of total solids is highest with the Jersey 
and low^t with the Holstein. The fat represents 34.9 per cent of the 
total solids with the Jersey breed and 28 per cent for the Holsteins. 
The relation of the fat to the total solids is influenced by breed espe- 
cially and to some extent by the individual in the breed. 

3. The data corroborate the well-known facts regarding the 
variations in fat content due to breed. 

4. The breed exerts a decided influence upon the protein content. 
A low average percentage of fat goes with a low protein content, 
although the ration is not constant. Breeds such as the Jersey, 
having a high fat content in the milk, also have a high protein con- 
tent; they also have a higher ratio of fat to protein. 

5. The proportion of the total protein pres^it as casein does not 
seem to bear any special relation to the breed, although some indi- 
vidual variations are observed. 

6. The ratio of casein to the &t varies uniformly with the breed. 
The variation between the Ayrshire, Shorthorn, and Holstein is slight, 
but the Jersey has more fat in proportion to the casein. 

7. The sugar content of milk does not show much variation either 
with the breed or with the individual. Our data showed a somewhat 
lower figure for the Holsteins than for the Ayrshires, Shorthorns, or 
Jerseys. 

8. The data presented show the well-known breed characteristics 
regarding the size of the fat globules, those in the Jersey being the 
lai^est, followed in order by the Shortliom, Ayrshire, and Holstein. 



SUMMABY AND CONCLUSIONS. 27 

9. The breed apparently is a factor having some influence on the 
Reichert-Meissl number. The highest was found with the Jersey, 
while the Holsteins had somewhat lower figures. 

10. The influence of the breed is shown on the iodin number. The 
Holsteins and Shorthorns have a noticeably higher number than 
the Jersey, with the Ayx^ coming between.^ ^ 

11. Little mfluence due to breed or individuality can be observed 
with the saponification number. 

12. The melting point of the fat shows no variation that may be 
attributed to breed and but little with the individual animals. 

13. With the exception of the size of the fat globules, the fat con- 
stants are far less influenced by the breed and the individuality of the 
animals than by the stage of the lactation period. The feed of the 
animal is probably a greater factor than breed or individuality in 
influencing the nature of the fat. 



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U. S. DEPARTMENT OF AGRICULTUfLE, 



iMied JkDliary 17, UIB. 



BUREAU OF ANIMAL INDUSTRY.— BULLETIN tU, 

A. D. MELVIN, Chup o» Burtiu. ' ' 



VARIATIONS IN THE COMPOSITION AND PROPERTIES 
OF MILK FROM THE INDIVIDUAL COW. 



C. f1. ECKLES, 

Profeiior tif Dairy Husbandry, University of Miuouri, 

AND 

ROSCOE H. SHAW, 
. Chetnist, Dairy Division, Bureau of minimal Industry, 



Ivaed January IT, IBIS. 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 157. 

A. D. MELVIN, Chdf op Butuu. 



VARIATIONS IN THE COMPOSITION AND PROPERTIES 
OF MILK FROM THE INDIVIDUAL COW. 



BV 

C. H. ECKLES, 

Professor of Dtxiry Husbandry, University of Missouri, 

AND 

ROSCOE H. SHAW, 

Chemist, Dairy tHvision, Bureau o/ Animal Industry. 



BUREAU OF ANIMAL INDUSTRY. 



Chief: A. D. Melvin. 

Assistant Chief: A. M. Farrinoton. 

Chief Clerk: Charles C. Carroll. 

AnxTnal Husbandry Division: George M. Rommel, chief. 

Biochemic Division: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsay, chief. 

Meat Inspection Division: Rice P. Steddom, chief. 

Pathological Division: John R. Mohler, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: £. C. Schroeder, superintendent. 

Editor: James M. Pickens. 

DAIRT DIVISION. 

B. H. Rawl, Chief. 

H ELMER Rabild, in diarge of Dairy Farming Investigations. 

S. C. Thompson, in charge of Dairy Manufacturing Investigations, 

L. A. Rogers, in charge of Research Laboratories. 

Ernest Kelly, in charge of Market Milk Investigations. 

Robert McAdam, in charge of Renovated Butter Inspection. 

2 



ADDITIONAL COPIES of this pablioatkm 
xl. may be procured from the SursBomHD- 
XMT or DocuMXNTB, Oovemment Piintliig 
Offloe, Washington, D. C, at 5 cents per copy 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

Bureau of Animal Industry, 
WasUngUmj D. (7., July 12, 1912. 

Sm: I have the honor to transmit, and to recommend for publi- 
cation as a bulletin in the bureau series, the accompanying manu- 
script entitled *' Variations in the Composition and Properties of 
Milk from the Individual Cow,'' by Messrs. C. H. Eckles, professor 
of dairy husbandry, University of Missouri, and Roscoe H. Shaw, of 
the Dairy Division of this bureau. 

This paper is the third in the series of reports on milk-secretion 
investigations which are being conducted at the Missouri Agricul- 
tural Experiment Station in cooperation between the Dairy Divi- 
sion and the Missouri station. The previous reports, which have 
been prepared for publication as Bulletins 155 and 156 of this bureau, 
have dealt respectively with the influence of the stage of lactation 
and the influence of the breed and individuality of the cows upon 
the composition of the milk. 

Respectfully, A. D. Melvin, 

Cliief of B'urea'u . 

Hon. James Wilson, 

Secretary of Agriculture. 

S 



CONTENTS. 



Introduction 7 

The animalH used, feed and management 8 

Methods of sampling and preparation of samples for analysis 9 

The variations from milking to milking 9 

Protein 9 

Sugar 10 

Fat 11 

The Reichert-Meissl number 11 

The iodin number 12 

The saponification number 13 

The melting point 13 

Comparison of morning and evening milk 14 

The composition of the first and last milk drawn 16 

Appendix— Tables I, II, and III 20 

5 



VARIATIONS IN THE COMPOSITION AND PROPERTIES OF MILK 

FROM THE INDIVIDUAL COW. 



INTRODUCTION. 

This is the third in a series of reports giving the results of investi- 
gations in regard to the influence of certain factors upon the compo- 
sition and properties of normal milk. Previous publications have 
given data in regard to variations due to the stage of lactation and 
variations due to the breed and individuality of the animal.* The 
present paper gives data concerning three factors in the milk from 
the individual cow, namely, (1) the normal variations from milking 
to milking, (2) the composition of morning compared with evening 
milk, and (3) the composition of the first as compared with the last 
milk drawn. 

It is a well-known fact that the composition of milk, at least so far 
as the percentage of fat is concerned, varies constantly and often quite 
widely from day to day, and even from milking to milking. No 
further investigation would be necessary to establish this fact, although 
it is impossible to set any definite limits as to what may be expected 
in this respect. Among the causes that are usually assigned for 
these variations is the influence of weather conditions, changes in 
the health of the animal, change in milkers, unusual excitement of 
any kind, and to some extent changes in feed. In many cases it is 
not possible, with our present knowledge of the physiology of milk 
secretion, to connect the variations noted with the cause. While the 
facts regarding the variations in the fat content are well known, the 
information is very meager regarding the other constituents of the 
milk, and especially regarding the composition of the fat itself. 

Some of the data already published show the variations throughout 
an entire lactation period. It may be pointed out, however, that a 
statement of this kind regarding the protein content, for example, 
really shows the influence due to the stage of lactation rather than 
to the daily variations. In order to obtain a fair idea as to the amount 
of daily variations to be expected, the periods covered should not be 
long enough to introduce variations due to the stage of lactation. 
Other conditions, as the feed and management of the animal, should 
remain constant. The variations which will then be found can rea- 
sonably be attributed to other causes, such as the physiological con- 
dition of the animal. 



1 BuUetiDS 155 and 156, Bureau of Animal Industry. 
54607O— Bull. 167—13 2 



8 VABIATIOKS IN MILK FBOM INDIVIDUAL COW. 

A more extensive knowledge regarding the daily variations in the 
composition of the milk is of importance to those engaged in the 
manufacture of dairy products on account of the relation it bears to 
the manufactured article. A knowledge of the extent and nature of 
these variations from milking to milking is perhaps of the greatest 
importance in connection with the use of milk as food, especially for 
infant feeding. For such purposes it is highly desirable to know if 
the constituents of the milk, such as the protein and sugar, vary from 
ihilking to milking, as the fat is known to do, or whether these con- 
stituents remam reasonably constant. So far little is known regarding 
the relation of the nature of the fat to its use as food, but whatever 
importance may be attributed to this factor, it is well to know what 
variations to look for from one day to another. The chemist who is 
concerned with the inspection of milk for the purpose of detecting 
adulteration is also greatly in need of this information, and he is 
constantly required to employ all available knowledge on this subject. 

Another reason for beginning this particular series of investiga- 
tions was the question of daily variations in connection with the 
sampling of milk from individual cows where the period of investi- 
gation covers a considerable length of time. The question here con- 
cerned is, How long a period must be included in the sample to obtain 
a fair representation of the composition of the milk the animal is 
producing? For example, in carrying on investigations m regard to 
the influence of feed upon the properties of milk it might be possible 
to obtain an entirely erroneous idea as to the composition of the 
milk and the nature of the fat if daily variations in the composition 
of the fat are large and the sampling period is short. 

THE ANIMALS USED, PEED AND MANAGEMENT. 

The animals used were all purebred registered animals of the 
breeds indicated. The following statement gives the details regard- 
ing the individuals supplying the samples analyzed : 



Cow No. 



303 (milked twice daily) 

205 (milked twice daily ) 

209 (milked twice daily) 

320 (milked twice daily) 

400 (milked twice daily) 

200 (milked three times dallv) . 
207 (milked four times daily) . . 



Breed. 



Ayrehlre.. 
Holstein.. 

do 

Jersey 

Shorthorn. 
Holstein.. 
do 



Age 

(years). 



3 
6 
5 
11 
6 
6 




Days in 
mJlk. 



180 
89 

289 
96 

102 
44 
14 



In carrying out these experiments the animals were fed a uniform 
ration both in kind and amount during the period covered by the 
samples. In this way variations due to the ration fed were elimiiiiated. 
The cows were milked by the same milker, and the intervals between 
milkings were uniformly 12 hours, except in the cases of cow 209, 



• VABIATIONS FROM MILKING TO MILKING. 9 

milked three times daily at eight-hour intervals, and cow 207, milked 
four times daily at six-hour intervals. Cows 206, 320, and 400 were 
fed a ration consisting of alfalfa hay, 2 parts, and a mixture of corn, 
bran, and oats, 1 part. Cows 303 and 209 were turned in a blue- 
grass pasture during the day, and in addition received a uniform 
grain ration consistmg of a mixture of com 4 parts, bran 2 parts, 
and linseed-oil meal 1 part. 

Cow 209 when milked three times dailv and cow 207 when milked 
four times daily received a still different ration, but the proportion 
between the constituents was kept the same and the total quantity 
fed daily was the same in order that the variations found could not 
be attributed to the feed. 

METHODS OP SAMPLING AND PREPARATION OF SAMPLES FOR 

ANALYSIS. 

The milk was weighed immediately after milking and the entire 
amount brought to the laboratory. From this a subsample was pre- 
pared for analysis. The cream was separated from the remainder of 
the milk with a small cream separator and the cream secured was 
churned in a glass j ar. This butter was melted to supply the fat sample 
for analysis. The measurements of color of the buttei*f at were made 
with the Lovibond tintometer. The methods followed in the chem- 
ical analyses are those recognized by the Association of Agricultural 
Chemists.* Further details in regard to the methods followed will be 
found in the first report of these investigations in Bulletin 156, 
Bureau of Animal Industry. 

THE VARIATIONS FROM MILKING TO MILKING. 

The detailed analyses of the milk from each of the 7 cows in this 
investigation are found in the three tables forming the Appendix at 
at the end of this bulletin. Table I shows the variations from milk- 
ing to milking of the 5 cows which were milked twice daily. Table II 
gives the data for cow 209 milked three times daily, and Table III for 
cow 207 milked four times daily. 

PROTEIN. 

Table 1 below is a summary showing the variations in total protein 
for the 7 animals. The most striking fact in regard to the protein is 
the comparatively small variation. More than 90 per cent of the 
analyses made showed a variation of less than 0.2 per cent from the 
average for the animal supplying the sample, and no samples show 
a variation of more than 0.3 per cent from the average. As com- 
pared with the other constituents of milk and with the composition 
of the fat these variations are small. The conclusion to be drawn 
from this is that the variation in the total protein from milking to 

> See Bulletin 107 (revised), Bureau of Chemistry, U. S. Department of Agriculture, 1908. 



10 



VARIATIONS IN MILK FROM INDIVIDUAL COW. 



milkJTig is comparatively smaU, and only in exceptional cases would 
it be sufficient to be of importance in connection with the use of milk 
as human food. From the standpoint of taking samples for chemical 
analyses these variations would have to be taken into account, but 
a fair sample regarding the amount of protein in the milk of a certain 
cow may be secured by taking the average of a comparatively few 
samples. 

Table 1. — Average varialwriB in total protein from viilking to milking. 



Cow No. 



303 
205 
200 
320 
400 
209 
207 



[milked 
milked 
milked 
milked 
milked 
milked 
fmUked 



twice daily) 

twice dally) 

twice daily) 

twice daily) 

twice daily) 

three times daily), 
four times dally).. 



Breed. 



Ayrshire.. 
Holstein.. 
....do.... 

Jersey 

Shorthorn. 
Holstein.. 

> ■ • • • ^*v • • • • 



Num- 
ber of 
milk- 
ings. 



28 
28 
28 
28 
28 
21 
20 



Total protein. 



Percent. 
3.21 
3.02 
3.31 
3.58 
3. 59 
2.75 
2.57 



Highest 



Percent, 
3.38 
3.19 
3.45 
3.83 
3.83 
3.19 
2.74 



Lowest 



Percent. 
2.93 
2.74 
3.13 
3.32 
3.45 
2.55 
2.30 



Variations flrom 
average. 



than 0.2 
percent 



Percent. 
93.0 
96.4 

loao 

89.3 
93.0 
95.0 
90.0 



Between 

0.2 and 

0.3 per 

cent 



Percent. 
7.0 
3.6 



10.7 
7.0 
&0 

10.0 



SUGAR. 

Table 2 is a summary showing the extent of variations in the sugar 
content. The sugar is usually considered to be the least variable of 
any coilstituent of milk, but our results indicate that it may be ex* 
pected to vary rather more than the total protein. Some animals 
seem to show a wider variation in the amount of sugar than others. 
A variation of 0.5 per cent from the average is not uncommon with 
certain individuals, but about 90 per cent of the analyses show a 
variation of less than 0.2 per cent. 

Table 2. — Average variations in sugar from milking to milking. 





Breed. 

Ayrshire.. 
Holstein . . 

...do 

Jersey 

Shorthorn 
Holstein.. 

...do 


Num- 
ber of 
milk- 
ings. 


Sugar content 


Variations from average. 


Cow No. 


Aver- 
age. 


High- 
est 


Low- 
est 


Less 

than 

0.2 per 

cent 


0.2 to 

0.4 per 

cent 


0.4 to 

0.6 per 

cent 


0.6 to 

a8per 

cent 


303 (milked twice daily). 
205 (mlUced twice daUy). 
200 (milked twice dally). 
320 (milked twice daily). 
400 (milked twice daily). 
209 (milked three times 

daily). 
207 (milked four times 

daily). 


28 
28 
28 
28 
28 
21 

20 


Perd. 
5.32 
5.10 
4.55 
4.91 
6.37 
4.68 

4.55 


Perd. 
5.65 
5.49 
5.05 
5.46 
5.70 
5.23 

4.n 


PereL 

4.98 
4.64 
4.29 
4.54 
4.83 
4.46 

4.25 


Perd. 
80.3 
35.7 
80.0 
46.4 
81.4 
85.0 

90.0 


Perd. 

10.7 
67.1 
7.1 
30.2 
14.8 
10.0 

10.0 


Perd. 


Perd. 


7.2 
3.6 

ia6 

""5.6' 


3.*i 

3.7 







VARIATIONS FROM MILKING TO MILKING. 



11 



FAT. 

As already stated, it is a well-known fact that the fat varies from 
nnillcing to milking. Table 3 gives the variations with this constituent 
for the 7 cows used in this investigation. The extreme variation 
reaches almost 2 per cent. Only 56 per cent of the samples come 
within 0.3 per cent of the average; 27.7 per cent range between 0.3 
and 0.6 per cent ; 11.7 per cent vary between 0.6 and 0.9 per cent from 
the average, and 4.6 per cent vary more than 0.9 per cent from the 
average. 

A sample taken from a single milking is of little va^ue as an indica- 
tion of the quality of milk produced by any cow. When the number 
of miUdngs per day is increased to three or four the variations in the 
fat content become greater. 

Table 3. — Average variations in fat content from milting to milking. 



■ 


Breed. 


Num- 
ber of 
milk- 
ingk 


Fat content. 


Variations fljrom average. 


Cow No. 


Aver« 
age. 


HJjg. 


Low- 
est 


Less 

than 

0.3 per 

cent. 


Be- 
tween 
0.3 and 
0.6 per 
cent 


Be- 
tween 
0.6 and 
0.9 per 
cent 


Over 

0.9 per 

cent 


303 (milkeditwloe daUy ). 
206 <Tnllked twice daUy ). 
aoo (milked twice daUy ). 


A3rT8hire . . . 
Holsteln... 

do 

Jersey 

Shortbom.. 
Holsteln... 

do 


27 
28 
28 
28 
27 
20 

19 

• 


Peret. 
3.1» 
3.07 
8.18 
5.31 
4.08 
2.06 

2.62 


Peret. 
4.36 
3.79 
8.67 
6.31 
6.20 
3.63 

4.15 


Perct. 
8.40 
2.40 
2.71 
4.56 
8.46 
2.24 

1.67 


Perct. 

77.7 
39.3 
86.7 
50.0 
63.0 
45.0 

31.6 


Perct. 
22.3 
46.4 
14.3 
25.0 
29.6 
30.0 

26.2 


Perct. 


Peret. 


14.3 




820 (mOked twice daily). 
400<inllked twice dftUy }. 
200 (milked three times 

daily). 
207 (milked four times 

daily). 


17.9 

3.7 

25.0 

21.1 


7.1 
3.7 

21.1 



THE REICHERT-MEISSL NUMBER.' 

Table 4 gives the data regarding this constant of the fat and shows 
what may be expected in the way of variations. The limit of error 
in making this determination is generally considered to be 0.5. 
Fifty-eight per cent of the determinations vary less than 1 from the 
average; 23.4 per cent vary between 1 and 2; 13.4 per cent between 
2 and 3; 4.6 per cent between 3 and 4; and 0.5 per cent more than 4. 

1 This and the soooeeding constants of the fiat were determined by official methods, the details of which 
may be foond hi Bulletin 107 (revised). Bureau of Chemistry, United States Department of Agriculture. 
For the benefit of those who may be unftoiillar with the tenns the following explanation may be helpful . 
The Reicliflrt-MeisBl ntunber is an arbitrary measure of the volatile adds of which butyric is the principal 
one in batterftit. The flguiee do not show the percentages of the acid, but serve as a means of comparing 
dlflerent fats with refBrenoe to their volatile constituents. The iodin absorption number Indicates relatively 
the amount of iodin a fat will absorb. Since the only fatty add found to exist in butteri^t whidi has the 
property of aboorbing iodin is oleic add, the iodin absoiption number shows relatively the amount of this 
tetty add present, but In common with the Reichert^Meissl number the figures do not represent peroentages. 
The saponification number Is the number of milligrams of potassium hydroxid required to saponify 1 grem 
of fst. Since the amount of potassium hydroxid required depends upon the molecular weight of the fat, the 
saponification number serves as an indicator of the relative percentages of the laity adds of higli and low 
moleailar weights present. 



12 



VABIATIONS IN MTLK FROM INDIVIDUAL COW. 



On the whole, the fluctuation in the Reichert-Meissl number is quite 
marked. It is impossible to say with our present knowledge what 
are the causes of this wide fluctuation. It is evident that to obtain 
a fair sample for this determination more than one milking should be 
represented. The authors have been unable to find any data regard- 
ing the significance of the amount of volatile acids from the stand- 
point of human food. 

Table 4. — Average variations in the Reichert-MeisBl number from milking to milking. 





Breed. 


Num- 
ber of 
milk- 
ings. 


Relchert-Meissl 
number. 


Variations from average. 


Cow No. 


Aver- 
age. 


High- 
est 


Low- 
est. 


Less 
thanl. 


Be- 
tween 
land 

2. 


Be. 

tween 

2 and 

3. 


Be- 
tween 
3 and 

4. 

P.ct. 
3.7 
3.5 


Above 
4. 


303 (milked twice dally) 
205 (milked twice daily ). 
209 (milked twice daily). 


Ayrshire... 

Holstein... 

do 


27 
28 
27 

27 
27 
21 

20 


21.99 
27.35 
19.24 
25.89 
26.15 
29.16 

30.67 


24.14 
30.81 
23.65 
28.01 
28.81 
30.43 

34.28 


18.46 
25.90 
18.39 
23.77 
23.45 
27.60 

27.15 


P.ct. 
44.4 
68.0 
70.4 
51.9 
70.4 
8L0 

20.0 


P.ct. 
33.3 
25.0 
18.6 
37.0 
11.1 
19.0 

20.0 


P.ct. 

18.6 

3.5 

7.4 

11.1 

18.5 


P.ct, 
3. 6 


320 (milked twice daUy). 
400 (milked twice daily). 
209 (milked three times 

d^ly). 
207 (milked four times 

dally). 


Jersey 

Shorthorn.. 
Holstein... 

do 












35.0 


25.0 





THE lODIN NUMBER. 

Table 6 shows the variations in the iodin number. The limit of 
error in making this determination is generally considered to be 0.5. 
The table shows that only 48 per cent of the total came within 1 of 
the average for the cow suppljdng the sample; 27.4 per cent varied 
between 1 and 2; while 15.8 per cent ranged between 2 and 3 from 
the average; and 8.8 per cent varied more than 3. These data indi- 
cate that rather wide variations are to be expected in the iodinnumber 
from day to day. 

Table 5. — Ai^erage variations in the iodin number from milking to milking. 





Breed. 


Num- 
ber of 
milk- 
ings. 


Iodin number. 


Variations from average. 


Cow No. 


Aver- 
age. 


High- 
est. 


Low- 
est. 


Less 
than 1. 


Be- 
tween 1 
and 2. 


Be- 
tween 2 
and 3. 


Above 
3. 


303 (milked twice daUy). 
205 (milked twice dally). 
209 (milked twice daily). 
320 (milked twice daily). 
400 (milked twice daUy). 
209 (milked three times 

dfldly). 
207 (milked four times 

daily). 


Ayrshire. . 
Holstein.. 

do.... 

Jersey 

Shorthorn 
Holstein.. 

do 


28 
28 
28 
28 
28 
21 

20 


41.32 
32.70 
41.98 
24.18 
30.63 
32.73 

41.17 


44.62 
34.46 
45.37 
28.27 
31.91 
34.49 

44.34 


40.04 
30.17 
34.28 
21.98 
28.77 
30.73 

38.28 


Perct. 
25.9 
71.4 
18.5 
69.3 
63.0 
47.6 

50.0 


Perct. 
25.9 
25.0 
33.3 
22.2 
87.0 
33.3 

15.0 


Perct. 

29.6 

3.6 

22.2 

11.1 


Perct. 
18.5 

'"*26!6 
7.4 


19.1 
25.0 


10.0 



VABIATIONS FROM MILKING TO MILKING. 



13 



THE SAPONIFICATION NUMBER. 

Table 6 is a summary of the variations in the saponification num« 
ber as found with the 7 cows. The limit of error in making this 
determination is considered as being 2. The table shows that on 
the average 62.2 per cent of the determinations varied less than 2 
from the average, or no more than the limit of error; 24.7 per cent 
ranged between 2 and 4 of the average; 9.3 per cent between 4 and 
6; while 3.7 per cent varied more than 6. As with the other con- 
stants of the f at, we find here considerable variation from milking to 
milking. A study of the tables fails to indicate any relation between 
the iodin number and the amount of fat or of any other constituent. 
An increase in the iodin number in most cases is accompanied by a 
decline in the Reichert-Meissl number and in the saponification "value. 
This relation is commonly found in butterfat. 

Table 6. — Average variations in the wponificalion number from milking to milking. 





Breed. 


Num- 
ber Of 
milk- 
Ings. 


Saponlflcatkm number. 


Variations from average. 


Cow No. 


Aver- 
age. 


Hse- 


Low- 
est. 


Ltss 
than 2. 


» 

Be- 
tween 2 
and 4. 


Be- 
tween 4 
and 6. 


Above 
6. 


308 (milked twice daUy). 
306 (milked twice daily). 
200 (mlllred twice daily). 
320 (milked twice daUy). 
400 (milked twice daily). 
200 (milked three times 

daily). 
207 (miked four times 

daUy). 


Ayrshire.. 
Holstein. . 

do 

Jersey 

Shorthom. 
Holstein.. 

• • • • *Uwa •••• 


28 
28 
28 
28 
28 
21 

20 


236.2 
227.0 
234.2 
235.3 
232.7 
230.1 

226.3 


247.3 
234.0 
242.4 
240.8 
230.7 
232.1 

231.0 


231.2 
224.6 
226.1 
232.1 
224.2 
236.6 

223.1 


Perct. 

48.2 
67.8 
42.3 
66.7 
70.4 
00.6 

60.0 


Perd. 
38.3 
21.4 
10.2 
22.2 
22.2 
0.5 

45.0 


Perct. 

11.1 

7.2 

30.8 

11.1 


Perct, 
7.4 
3.6 
7.7 

7.4 


6.0 





THE MELTING POINT. 

A summary of the data showing this constant of the fat is given in 
Table 7. The range in variation here is small. It may be seen that 
96.5 per cent of all vary less than 1® from the average. This result 
corresponds with our data already published in indicating that the 
melting point of the fat is not influenced to any great extent by a 
small change in the other constants of the fat. The melting point of a 
mixture of fats can not be predicted from the melting points of the 
fats themselves, according to Lewkowitsch.^ 

I Lewkowltach, J. Chemical technology and analysis of oUSi tats, and waxes. London, 1000. See vol. 1» 
p. 04. 



14 



VARIATIONS IN MILK FROM INDIVIDUAL COW. 



Table 7. — Average variations in the melting point from miliiTig to milting. 





Breed. 


Num- 
ber of 
milk- 
ings. 


Melting point. 


Verlations from 
average. 


Cow No. 


ATOage. 


Highest. 

• 


Lowest. 


Less 

than 

1 degree. 


Between 
land 2 
degrees. 


303 (milkfMl twice daUy) 

205 (milked twice daUy) 


Ayrshire 

Holstein 

do 


28 
28 
28 
28 
28 
21 
20 


•a 

33.34 
84.09 
33.46 
36.43 
33.92 
82.54 
34.01 


•c. 

34.45 
85.06 
34.40 
86.10 
34.40 
34.27 
34.97 


•c. 

32.30 
33.30 
32.95 
34.56 
33.46 
81.57 
33.40 


Percent. 

88.9 
100.0 

96.3 
100.0 
100.0 

90.6 
100.0 


Percent. 
11.1 


209 (milked twice daUy) 


3 7 


320 (milked twice daUy). :... . 


Jeney 

Shorthorn... 

Holstein 

.... .do..... . . 




400 (milked twice daUy) 




209 (milked three times daily) . 
207 (milked four times daily}.. 


9.6 









COMPARISON OP MORNING AND EVENING MILK. 

The data which have been given make it possible to compare the 
composition of morning milk with that milked in the evening. A 
large amount of data is already available regarding the variation in 
the fat content of milk as brought about by this factor. Practically 
none, however, has been published regarding the variations in the 
constituents other than the fat or regarding changes in the nature of 
the fat itself. 

Fleischmann * found morning milk slightly richer than evening, but 
decided that the fat content varied with the interval between milkings. 
Sufficient data have been published by various authors to show the 
accuracy of the above statement. As a rule, when a cow is milked 
twice daily at intervals of equal length there is only a small variation in 
the average fat content of the milk. The variations found under 
these conditions seem to depend upon the individuality of the 
animals. 

Table 8 is compiled from those that have preceded and gives the 
average figures for the morning and evening milking for each animal. 
Taking first the animals where the interval between milking was 
uniformly 12 hours, it will be noted that with 4 out of the 5 cows the 
yield of milk was slightly greater in the morning. 

No variation in the protein content can be observed that may be 
attributed to the factor under consideration. The same may be said 
of the sugar. The fat is noticeably higher in the morning with 3 
of the cows and apparently unchanged with 2. 

The Reichert-Meissl number with each of the 5 animals is lower in 
the evening. 

The iodin number in each case is higher in the evening sample. 

The saponification value for the evening sample is decidedly lower 
with 2, slightly lower with 2, and higher for 1. 

The melting point shows no variation sufficient to be taken into ac- 
count. The same is true in regard to the size of the fat globules. 

1 Fleiachmann, Wilhelm. Untersuchung der Milch von sechssehn Kiihen. Landwirtsnhaftlirthd 
JahrbOcheTi vol. 20, sup. 2. Berlin, 1891. 



COMPARISON OP MORKIKG AND EVENING MILK. 



15 



The phjnsical constants of the fat show slight variations, but hardly 
sufficient to be taken into account. 

The samples from the 2 animals that were milked three and four 
times daily showed wider variations than those from the cows milked 
twice only, although no appreciable variation was foimd with the 
total protein, sugar, and ash. 

The per cent of fat varied considerably with the different milkings. 
The highest fat content was found in milk dravm near the middle of 
the day. 

In general the composition of the milk plasma does not seem to vary 
appreciably from morning to evening when the interval between 
milkings is the same. This statement also holds good when the 
number of milkings is increased from two to three or four per day. 
The per cent of fat shows some variation, mostly depending upon the 
individual^ and this variation is wider when the cow is milked more 
than twice daily. The fat content of morning milk is usually slightly 
higher. There seems to be a fairly constant variation in the chemi- 
cal and physical constants of the fat between morning and evening. 
This is most noticeable with the volatile acids, which tend to be 
higher in morning milk, and with the iodin number, which is gen- 
erally higher in the evening sample. 

Table 8. — Comparison of morning and evening milk — Avo'oge determinations for each 

milking. 

cows MILKED TWICE DAILY. 



Cow 

No. 



308... 
205... 
200.., 
320... 
400.. 





Aver- 


Total 








Reich- 
ert- 


lodin 


Sapon- 
ifica- 


Melt- 
ing 

point 
of fat. 


Hoar milked. 


yield, 
ofmnir. 


pro> 
teln. 


Aah. 


Sugar. 


Fat. 


Meifll 

xuim- 

ber. 


num- 
ber. 


tion 
num- 
ber. 




Pounds, 


Peret. 


Peret, 


PercL 


Perct. 








•c. 


r5.30a.m 


11.2 


3.16 




6.37 


3.96 


22.92 


38.94 


238.1 


33.37 


15.30 p. m 


12. > 


3.24 




5.26 


3.92 


2L12 


43.33 


234.4 


33.31 


5.30 a. m 


9.2 


3.00 




5.24 


3.45 


27. S2 


32.53 


227.7 


34.13 


5.30 p. m 


8.0 


2.95 




4.96 


2.70 


7:1. n 


32.87 


228.2 


34.05 


<5.30a.m 


14.4 


3.28 




4.57 


3.17 


20.52 


41.60 


235.5 


33.35 


&30p.m 


13.6 


3.33 




4.54 


3.18 


19.43 


42.34 


23L9 


33.56 


15.30 a. m 


10.1 


3.63 




4.92 


5.64 


26.24 


23.50 


235.8 


35.45 


i5.30p.in 


9.2 


3.54 




4.84 


4.96 


25.55 


24.53 


234.9 


35.40 


(5.30 a. m 


10.1 


3.57 




5.41 


4.26 


26.54 


20.59 


232.8 


83.98 


\5w30p.m 


9.3 


3.61 




5.32 


3.88 


25.88 


30.97 


232.7 


33.85 



Rel*- 

tive 

Bixeof 

fat 

glob. 

ules. 



132 
139 
161 
133 
68 
68 
373 
322 
420 
384 









cow MILKED THREE TIMES DAILY. 




■ 




209:.. 


i5a. m 

Ip.m 

9p. m 


23.7 
19.1 
14.9 


2.73 
2.70 
2.82 


0.73 
.71 
.72 


4.77 
4.53 
4.73 


2.47 
3.26 
3.25 


29.49 
29.39 
28.60 


3L75 
33.01 
33.43 


23L1 
230.2 
229.1 


32.40 
32.38 
32.83 


70 
67 
73 








cow MILKED FOUR TIMES DAILY. 






• 


207... 


4 a. m 

10 a. m 

4p. m 

lOp. m 


28.1 
23.0 
23.2 
22.3 


2.62 
2.57 
2.63 
2.46 


0.72 
.72 
.73 
.70 


4.01 
4.48 
4.61 
4.50 


2.07 
3.46 
2.51 
2.60 


30.41 
30.75 
30.82 

saas 


40.63 
4L19 
4L06 
41.79 


226.4 
226.0 
226.4 
226.8 


34.27 
83.99 
83.77 
33.98 


160 
166 
153 
224 



16 



VARIATIONS IN MILK FROM INOmOUAL COW. 



^ THE COMPOSITION OF THE FIRST AND LAST MILK DRAWN. 

It has long been well known that the last milk drawn from a cow, 
commonly known as the strippings, contains a much larger per cent 
of fat than does the first milk drawn from the same cow, often 
spoken of as the foremilk. Kirchner ^ gives figures typical of this 
variation. According to his data the fat content increases gradually 
as the milking progresses, while the solids other than fat remain 
practically constant in all parts of the milking. 

The investigation herein reported was made for the purpose of 
supplying additional data on this factor, especially in regard to the 
variation in the composition and nature of the fat in the foremilk 
and the strippings. This information is given in Tables 9 and 10. 
In taking the samples of foremilk represented in Table 9, 100 c. c. of 
milk was taken from each teat of the cow, the 4 portions being 
mixed to form the sample for analysis. The sample of strippings 
was secured when the milk was nearly out of the udder. A sample 
of 100 c. c. was then taken from each teat. If more could be drawn 
after taking this amount it was drawn into a second flask and suffi- 
cient added from the first to make up 100 c. c. One sample was 
then made by mixing the 100 c. c. sample from each teat. 

It is probable that a still more marked variation would have been 
found between the first and last milk drawn had the samples taken 
been smaller and thus represented the extremes of the milking. The 
samples supplying the fat for the analyses given in Table 10 were 
taken in the manner already described, except that the samples from 
each cow were put together in the form of a composite sample repre- 
senting 7 days. This was done in order to secure sufficient fat from 
which to make the determinations. 

The following is the average analysis of the first and last milk, 
taken from Table 9 : 



First mUk. 
Strippings. 



Total 
protein. 



Per cent. 
3.58 
3.38 



Sugar. 



Percent. 
5.30 
5.33 



Fat. 



Per cent. 
1.87 
6.28 



Ash. 



Per cerU. 

0.75 

.70 



Total 
solids. 



Percent, 
10.67 
14.86 



Holative 
siseoffat 
globules. 



139 
215 



iKirohner, W. Handbuch der Milch wirtschaft. Berlin, 1898. Seep. 56. 



COMPOSITIGN OF FIK8T AND LAST MILK DRAWN. 



17 



The only difference that is at all striking is that of the fat. Since 
the variation in this constituent is so marked, the following figures 
are given, which represent the composition of the milk plasma or the 
milk minus the fat: 



Total 
protein. 



Sufsar. 



Ash. 



FlntmUk. 
Stripptngs. 



Percent, 
3.66 
3.60 



PereetU, 
5.40 
5.68 



Percent, 

o.n 

0.75 



It is evident from these figures that the change in composition of 
the first milk drawn to the last is confined to the amount of fat 
present. The milk plasma remains practically the same in compo- 
sition. 

The data given in Table 9 show that the larger the quantity of 
milk produced the greater is the variation in fat content and in the 
relative size of the fat globules between the first and last milk drawn. 
From the further data in Table 10 it may be observed that the 
quantity of milk produced is an important factor in determining the 
extent of the variation from the foremilk to the strippings. With 
the cows producing the small quantity of milk the strippings range 
from twice to three times the fat content of the foremilk, while with 
those producing large quantities the strippings contain 3 to 10 
times as much as the foremilk. 

The higher fat content of the last milk drawn has been explained 
in several ways. The most plausible seems to be that given by 
Eirchner.^ According to this author the fat globules are held back 
mechanically in the fine passageways of the udder and escape in 
larger quantities in the last milk drawn. The data given support 
this theory by the additional fact, not given by the authority quoted, 
that the larger the production of milk the greater is the increase in 
fat as the milking progresses. This may be explained by the suppo- 
sition that in the heavier milking cows the udder is more congested 
and the opening of the ducts made smaller by compression. 

The lai^er fat globules would also be held back in the small ducts 
more than the smaller ones. This would account for the lai^er fat 
globules in the strippings and for the greater variation in size from 
foremilk to strippings when the production of milk is large. 



1 Kirchner, W. Handbuch der MUchwirtacbaft. Berlin, 1808 See p. 68. 



18 



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COMPOSITION OF FIRST AND LAST MILK DRAWN* 



19 



Table 10. — The composition o/theforefnilk and strippings as influenced by the quantity 

of milk produced. 





Total 
milk. 


Fat content 


*m 


Relative size of fat globules. 


Breed. 


Fore- 
milk. 


Entire 
milk. 


Strip- 
pings. 


Fore- 
milk. 


Entire 
milk. 


Strip- 
pings. 


Jerser 


Pounds. 

3.0 

3.0 

3.3 

4.0 

7.8 

8.1 

U5 

16.7 

12.7 

14.0 

16.7 

20.2 

20.2 

72. b 


Percent. 
Z.1 
3.5 
3.2 
3.8 
1.4 
1.0 
0.9 
0.4 
2.0 
1.0 
1.2 
0.2 
0.4 
1.0 


Percent. 
6.2 
5.3 
5.2 
5.4 
3.8 
3.8 
3.1 
2.5 
3.0 
2.0 
3.0 
1.3 
1.6 
1.6 


Percent, 
10.3 
7.4 
7.6 
10.0 
8.7 
8.8 
7.6 
7.0 
5.2 
3.0 
5.2 
4.0 
5.3 
3.4 


206 
88 

125 
76 

152 

244 
51 
24 

118 
21 
56 
13 
27 
60 


2SD 

148 

120 

84 

232 

140 

145 

04 

146 

29 

67 

59 

70 

70 


264 


Do 

Do 

Do 


178 
158 
109 


Shorthoni 


280 


Do 


224 


Do 


254 


Do 


108 


HolBtein 


150 


Do 


48 


Do 


00 


Do 


68 


Do 


122 


Do 


108 







Table 11 gives the physical and chemical constants of the fat as 
found in the first and last milk drawn. The following is an average 
of this table: 



First milk. 
Strippings. 



Reichert* 

Meissl 
number. 



27.25 
26.32 



lodin 
number. 



34.14 
33.82 



Saponifica- 
tion num- 
ber. 



230.1 
228.3 



Melting 
point 



33.88 
33.91 



Yellow 
color. 



39 
39 



The Reichert-Meissl number on the average is 0.93 lower in the 
strippings. It is lower with 6 out of the 8 cows supplying the sam- 
ples. 

The iodin number is 0.32 lower on the average in the fat from the 
strippings and 7 out of the 8 cows show the same variation, the eighth 
being practically the same. This tendency for a lower iodin number 
in the strippings while not great enough to be of much importance 
seems to be the rule. 

The saponification number also is lower on the average in the strip- 
pings and occurred vath 6 out of the 8 animals. 

The melting point of the fat and the yellow color seem to be 
unchanged. 



20 VARIATIONB IN MILK FROM INDIVIDUAL COW, 

Tabli U.—ATUtlynsof/at/TomJirtt and Uut milk. 



APPENDIX. 



The following tables give the detailed analyses of the milk at ^ach 
milking from the 7 cows specially used in this investigatiou. Table 
I contains the data tor the 5 cows milked twice daily, Table II gives 
the analyses for the cow milked 3 times dait^, and Table III for the 
cow milked 4 times daily. 




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28 



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454. 
■ tlu 

iMoed October 9, ItU. 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— BOLLETW 158. 

A. D. MELVW, Otat » BuuAlt. 



THE ROUNDWORMS OF DOMESTIC SWINE, 

WITH SPECIAL REFERENCE TO TWO SPECIES 
PARASITIC IN THE STOMACH. 



WINTHROP D. FOSTER, 
Junior Zoologist, Zoological Division. 



CONTENTS. 

Page. 

Summary 7 

Introduction 8 

Family Filarud«e 9 

SubfiEunily Arduenninse 9 

Genus Arduenna 9 

Arduenna stronffylina 10 

Arduenna dentata 20 

Genus Pky80cephalus "21 

Physocephalus seocalatuB 21 

Comparison of Physocephalus sexalatus and Arduenna strongylina 31 

Other species referred to Physocephalus sexalatus 31 

Distribution of Arduenna strongylina and Physocephalus sexalatus in ihe United 

States 32 

Relative frequency of the two species 34 

Lesions associated with Arduenna strongylina^ Arduenna dentata, and Physo- 
cephalus sexalatus 34 

Life history 36 

Preventive measures 37 

Medicinal treatment 37 

Key to the roimdworms parasitic in domestic swine 38 

Classified list of the roimdworms parasitic in domestic swine 41 

Bibliography 45 

5 



ILLUSTRATIONS. 



PLATE. 

Plate I. A portion of the pyloric end of ahog^sstomach, infested with Ardiunna 

stroTigylina and Phytocephahis gexalattu Frontispiece 

TEXT FIOUBEB. 

Page. 

Fig. I. Arduennastrongylina. Median view of cephalic end 10 

2. Arduenna strongylina. Bursa of male, ventral view 11 

3 . Arduenna strongylina . Posterior end of body of male, viewed from right 

side 12 

4. Ardtienna strongylina. Posterior end of body of female, viewed from 

leftside 12 

5. Arduenna strongylina. Ventral view of middle of body of female 13 

6. Arduenna strongylina. Lateral view of egg removed from a ruptured 

uterus 13 

7. Arduenna strongylina. Short spicule with retractor muscles, viewed 

from right side 14 

8. Arduenna strongylina. Posterior end of body of male, viewed from 

leftside 14 

9. Arduenna strongylina. Cross section through body of female in the 

r^ion of the vulva 15 

10. Arduenna strongylina. General view of body of male from ri^t side. 15 

11. Arduenna strongylina. General view of body of female from left side. 16 

12. Arduenna strongylina. Cephalic end 17 

13. Arduenna strortgylina. Bursa of male, ventral view 17 

14. Physocephahis sexalatus. Lateral view of cephalic end 18 

15. Physocephalus sexalatus. Lateral view of cephalic end 18 

16. Ardv£nna dentata. Median view of cephalic end 20 

17. Arduenna dentata. Bursa of male, ventral view 20 

18 . Physocephalus sexalatus. Dorsal view of anterior end of body 22 

19. Physocephalus sexalatus. Posterior end of body of male 23 

20. Physocephalus sexalatus. Bursa of male, viewed from left side 24 

21. Physocephalus sexalatus. Posterior end of body of female, ventral 

view 25 

22. Physocephalus sexalatus. Ventral view of body of female in the region 

of the vulva 25 

23. Physocephalus sexalatus. Lateral view of egg removed from a ruptured 

uterus 26 

24 . Physocephalus sexalatus . Bursa of male, ventral view 26 

25. Physocephalus sexalatus. Cross section through anterior part of body. . 27 

26. Physocephalus sexalatus. Ventral view of body of female 27 

27. Physocephalus sexalatus. Lateral view of anterior end of body 28 

28. Physocephalus sexalatus. General view of body of male 29 

6 



THE ROUNDWORMS OF DOMESTIC SWINE, WITH SPK3AL REF- 
ERENCE TO TWO SPECIES PARASITIC IN THE STOMACH. 



Two species of roundwonns belonging to the family Filariide, of particular interest 
to helminthologists and veterinarians on account of their wide distribution and fre- 
quency of occurrence in American swine and the possibility that they may cause 
serious injury to their host, are given special consideration in this paper. 

One of these species, identified as Spiroptera strongyHna, has recently been placed 
in a new genus, Ardwmna, of which it is the type, and eeveral erron rogaiding the 
anatomy of this parasite have been coirected. Another species, Arduenna denUUa, 
has been found in China associated with Arduenna strongylinaf and although not yet 
reported in American swine is mentioned in this connection, as further investigation 
may reveal its presence in this country. 

Arduerma gtrongylina is much more common in American swine than it is said to 
be in European swine, and has been found abundantly in the slaughterhouses at St. 
Louis, Chicago, South Omaha, and Kansas City, and has also been collected at Ben- 
ning, D. C, and Bethesda, Md. 

Specimens of hogs' stomachs received from Chicago showed the worms deeply 
fastened in the submucoea or embedded in necrotic tissue near which were deep 
ulcers. The condition suggested infection with Bacillua necropJioruSy the inoculation 
of which might easily result from the burrowing of the worms; however, owing to the 
sterile condition of the specimens received, this could not be satisfactorily demon- 
strated . A similar diseased condition of the stomachs of hogs in Europe is attributed 
by Von BiLtz (1899d)^ to infection with Arduenna stnyngylina. Under the circum- 
stances the worm should be regarded with grave suspicion, and general prophylactic 
measures for the prevention of the spread of infection are suggested. 

Commonly associated with Arduerma strongylina in this -country is another worm, 
identified as Phy»ooephalu8 texalatus^ first described by Molin (1860b) from specimens 
from the peccary (Dicotyks labiatus) from Brazil; also found by him associated with 
Anhienna strongylina from the wild boar in Germany. It is also reported by Von 
Linstow (1879b) (who apparently mistook this species for Arthienna strongylina) 
and Plana (1897e), from Europe, and by Railliet and Henry (1911b), from Madagascar 
and Indo-Qiina, in' the former case associated with a severe gastritis. Seurat (1912) 
has recently reported this species from the ass and dromedary in Algeria, but his 
statements would seem to require confirmation. 

According to the writer's experience, Physocephalus sexalatus is almost as widely 
distributed as Arduenna strongylina^ since out of eight lots of specimens of the latter 
species, specimens of Physocephalus sexalatus were found in all but one. In a mixed 
infection, however, it has never been found as abundantly as Arduenna strongylina. 
This worm has apparently the same habit of injuring the mucosa as has Anhienna 
stnmgylina^ as both species were found in the same necroUc tissue in a hog*s stomach. 
It miist therefore be considered only less dangerous because it is leas abundant, and 
should be subject to the same treatment suggested for infestation with Arduenna 
strongylina. 

1 Referenoes to litentare will be foond in bibliography at end of bulletin. 



8 THE ROUNDWORMS OF DOMESTIC SWINE. 

Nothing is known in r^;ard to the life cycle of these parasites, but their wide distri- 
bution and frequency of occurrence suggest a simple life history without an interme- 
diate host. The fact that the eggshells of both species are relatively thick would 
seem to indicate that the embryos are not liberated until the shell is dissolved by the 
gastric juice of the host. From the ^t that the embryos are fairly well developed 
before ovipoeition, it may be inferred that the eggs require but a short period of incu- 
bation. 

Following the discussion of the two species is a key for use in the identification of 
roimd worms parasitic in swine; also a list of these parasites classified according to their 
zoological position. 

INTBODTTCTION. 

Nematodes occurring in the stomach are commonly present among 
swine in the United States. These have usually been considered by 
veterinarians, pathologists, and others who have had occasion to 
mention them as belonging to the species Spiroptera sirangylina 
Rudolph], 1819, although some have expressed a doubt as to the cor- 
rectness of the identification. In addition to the forms which have 
been identified as Spiroptera sirongylina, Hassall and Stiles (1892a) 
have described a species named by them Strongylus rvMdus, and 
which has since been collected from domestic swine in Europe. 

Recently a zoological study of specimens of nematodes in the hel- 
minthological collection of the Bureau of Animal Industry, collected 
from the stomachs of hogs in various parts of the United States, was 
undertaken by the present writer, largely as a result of reports from 
inspectors relative to the prevalence of nematodes in the stomachs 
of swine, Drs. J. J. Brougham and T. B. Pote, of the St. Louis station, 
having been among the first in the Federal service to give attention to 
the subject from the standpoint of meat inspection. As a result of this 
study and of a comparison of these specimens with specimens of 
Spiroptera stronffylina received from Europe, the conclusion has been 
reached that in several particulars the descriptions of Spiroptera 
strongylina commonly given by European writers are in error, and 
that the forms commonly identified as Spiroptera strongylina represent 
two distinct species, one of them Spiroptera strongylinay the other cor- 
responding to Physocephalus sexalatus (Molin, 1860) Diesing, 1861, 
hitherto considered a rare parasite and until recently reported only 
once for domestic swine. 

According to Stiles and Hassall (1905b), the genus Spiroptera is 
preempted by the genus Acuaria Bremser, 1811, whose type is 
arUhuris. This species is also the type of Dispharagus Dujardin, 1845, 
a genus based largely on certain nematodes of birds and not found in 
mammals. According to this ruling, the genus Acuaria is confined to 
certain parasites of birds and fishes characterized by a differentiation 
in the structure of the esophagus. As Spiroptera strongylina does 
not conform to the type of Acuaria or the characteristics of the genus, 
a new genus to include these forms is necessary. This deficiency has 



THE BOUNDWOBMS OF DOMESTIC SWINE. 9 

been supplied by the creation of a new genus, ArduenvA^ by Railliet 
and Henry (1911), Spiroptera strongylina being taken as the type. 
Both Arduenna and PhysocepTialus, together with Simondsia paradaxa, 
belong in the family Filariidas,^ and are included by Railllet and 
Henry (1911b) in the new subfamily Arduenninae. 

Family FILARUDiE, Claus, 1885. 

Family diagnosis. — Nematoda: Body long, filifonn. Mouth sunoimded with 
papillae, or provided with two lips. Esophagus slender, without posterior bulb. 
Males with a single spicule or with two Unequal spicules. Females with two ovaries; 
vulva usuaUy in front of the middle of the body. UsuaUy ovoviviparous. Develop- 
ment in many cases requires an intermediate host. 

Typb obnus.— jFitena Mtlller, 1787. 

Bn'bfkixillir AJRDJTEINNINJS: liallliet luxd 'H.eiupy^ 1911. 

Subfamily diagnosis. — Filariidse: Mouth with two lateral lips leading into a 
pharynx marked with cuticular ridges in the form of spirals or rings. Spicules 
unequal, the longer several times the length of the shorter. Four pairs of preanal 
papulae. Eggs containing embryos when oviposited. 

Typb obnus. — Arduenna Railliet and Henry, 1911. 

Genus ARDUENNA Railliet and Heniy, 1911. 

Genbric diagnosis. — Filariidae: Body subcylindrical, attenuated anteriorly, 
posteriorly somewhat broader, usually curved in a semicircle, marked by a nairowi 
longitudinal cuticular wiag on the left side, extending nearly the length of the body. 
Cuticle densely striated transversely. Mouth with two lateral lips, each lip with 
three lobes, leading into a small buccal capsule containing two lateral teeth, and fol« 
lowed by a cylindrical pluuynx marked with cuticular ridges forming a series of spirals. 
Esophagus continuous, gradually broadening posteriorly and occupying from one- 
fourth to one-third of the body length. Caudal end of the male curved in a single 
turn. Bursa asymmetrical, the right bursal wing being broader than the left wing, 
furnished with five pairs of stalked papillse asymmetrically arranged, of which one 
pair is preanal, three pairs are adanal, and the fourth pair is postanal. Bursal mem- 
brane marked with longitudinal and transverse striae, giving it a wrinkled appearance. 
Anus surrounded by a cuticular thickening, serrated on the outside edge. Spicules 
long and very unequal, the longer five to seven times the length of the shorter. Vulva 
anterior of the middle of the body. Eggs with thick shells containing embryos at the 
moment of oviposition. Parasitic in the stomachs of Suidse. 

Typb specibs: Arduenna strongylina (Rudolphi, 1819), Railliet and Henry, 1911. 

i Dtodng (1861a) proposed the family name Spiruridea for a group of nematodes distingolshed tnm 
FUarta by the carl or spiral twist of the tail of the male. This family is not accepted by most recent writers 
on the ground that it is not based on sufQdently characteristic morphological fJeatores, and that the name 
does not conform to the roles of loological nomenclature. Oerley (18S5a), Leiper (1906), and Railliet and 
Henry (1911b) use the name SplmrldsB, apparently modifying Dlesing's (1861a) family name Spiruridea 
to confarm to the prannt soological nomenolature. The temily name Splropterlde is proposed by Letper 

0911). 

Owing, however, to the apparent invalidity of the name Spiroptera, the present writer prefers not to use 
either the family name Splruridie or Spiropteridse, and although it is evident that the genera Ariuenna 
and Ph^tooepkfihu, and other genera as well, will ultimately be separated from the FilarlldiB, it is not con- 
aldend desirable to attempt sooh a revision until a more careful study has been made of the various spedef 
involved. In the present paper, therefore, A rduenna and Phpncephalut are retained in the family FUarlidso 
but included under the subHomily Arduenninee, Railliet and Henry, 1911, 

62865*'— Bull. 158—12 2 



10 THE BOURDWOBHB OF DOMESTIC SWINE. 

ixdoemu stnmgfUiu (Rudolt^, 181B) Bailliet and Henry, 1911. 
1819: Spiroptera strongyliria RudolpM, 1819a, p. 23. 
1819: Spiropterv. strongylina Rudolphi, 1819a, p. 237. Maprint for 

Spiroptera. 
1828: Spiroptera strongyliformis De BliunTiUe, 1828a, p. 546. 
1866: FUaria strongylina (Rudolphi) Schneider, 1866a, p. 101. 



eitt 



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aoptitgui; io^ Vi 'bIiI^ P'I'Uk- P*'> pburmi t. A. e., t«tJ] ol Uia buooal npsule. X HO- (OrigtiaL) 

Spbcittc diaonobib. — Cuticule densely striated tranavereely, incieaeiiig in thickneaa 
toward the anterior extremity, which is furniehed with two cervical p&pillft placed 
aeymmetrically, the left being about 190 p. and the right 390 ^ from the anterior ex- 
tremity. Banning at a point 280 p. from the anterior end on the left aide, a narrow 
cuticular wing gradually increaaing to a maiimiim breadth of 35 ^ extends to a point 
about 2 mm, from the posterior extremity. Mouth 44 to 45 /i in diameter with two 
lateral lip« each with three lobee, having a amall round papilla at the baae of each ol 
the lobes. Just below the lipe and projecting into the mouth cavity are two chitinoua 
t«eth, formed by a prolongation of the wall of the pharynx (fig. 1). The pharynx, 29^ 



THE BOUNDWOBMS OP DOMESTIC SWINE. 11 

wide by 83 to 98 fi long, is marked on the inside by a seriefl of chitinousridgee in the 
form of continuous Bpirale (or a multiple epirol), all running in the same direction and 
appearing like the Ihreada of a quadruple screw. 

Baophagus3,l to3.7 mm. longjOrabout one-fourth of the body length, and 117 to 
127 fi wide at ite widest part near the bane. Nerve ring 0.35 nun. and excretory pore 
0.48 nun. from the anterior end. 

UaU 10 to 15 mm. long, averages about 13 mm. in lei^h; 301 to 387 fi wide at the 
wideot part just above the bursa. The bursal wings extend from a point about 1.2 
mm. from the caudal extremity to the tip, the body ending in a blunt point. Bursal 
wings irregularly ovale, 
asymmetrical, the right bur- 
sal wing being about twice 
as wide aa the left wing. 
The bursa contains 5 pairs 
of stalked papilke asym- 
metrically arranged, of 
which 4 pairs are preanal 
and the last pair is post- 
anal. Bursa marked with 
fine longitudinal striie, in- 
creasing in density toward 
its base (fig. 2). Spicules 
two, grooved on the ven- 
tral surface, the left spicule 
2.24 to 2.95 mm, long, 
very slender, ending in a 
fine ftoint and presenting 
a slightly concave sur- 
face near the tip on the 
dorsal side. The right 
spicule (about one-fifth of 
the length of the left spicule) 
is stouter and blunter at the 
point, measuring 10 n at its 
base, or nearly twice the 
width of the base of the 
long spicule, and is 457 to 
619 fl long (fig. 3). Anus 
155 to 200 ^ from the pos- 
terior end and surrounded 
on the posterior and left side 
by a cuticular thickening 
(circumanal ring), the outer 
edge of which is serrated. 

Frmalt 16 to 22 mm. long, 
263 to 420 ji wide; average maximum width 368 ;i, at a point about one- third of the 
distance from the head t« the caudal end. For the next third of the distance the 
width remains constant except for a slight constriction in the r^ion of the vulva. 
Beginning at a point about two-tbirda of the distance from the bead to the caudal 
end, where one of the uteri turns back on itself, the width gradually diminiahea and 
then abruptly decreases a short dislance in front of the anus. Anus 215 to 275 /i 
from the caudal tip (fig. 4). 

The orbicular naked vulva opening near the left side close to the lateral cuticular 
wing is slightly anterior of the middle of the body, dividing the worm anteriorly and 
postericM'ly in the ratb 5 :6, Vagina uniform, about 49 /i in diameter, 1.7 mm. long, 



Fio. 3,—ATiutnna unmgflina, Bulssol male, venlial vlev 
cloaca: I.b.w., lett bunaJ wlog; Ltp,, long spicule; po. p. 
unl papills; pr. p., pmiiial papillin; r. b. lo.. right bursal 
I. (p., nhort spicule: p. r. c, ventral ridge of Lbs ontlcle. 
(OrlgUwl.) 






12 THE BOUNDWOBXS OF DOHESTIO BWIITB. 

extendingiuageDerallypoateriordirectioa, joining the utariata point about 1.1 mm. 
from the vulva measured in a etraight line (fig. S). 

Eggaoval, 34 to 39 ;< long by 20 ;■ wide, with thick ehells. Embryo* well developed 
in the shell before ovipoeition (fig. 6). 

Hoots. — Domestic h<^ (Su* terofa damatiea), wild bow (Su» $iTofa/era). 

Location. — Stomach and email inteetine. 

LoGAUTiBs coLLBCTBD.— United States: Bethesda, Hd.; Benaing, D. C; Chicago, 
111.; South Omaha, Nebr.; St. Louis, Mo.; Kansas City, Mo.; Denver, Colo.; Brazos 



Fio. 3.—AidutBBa ttrong^lta. PoaUdia end ot 
body of male, viewed Inm rigbtitde. I. ip., long 
■pfcule; t. tp., abort spicule, x U. (Original.) 

County, Tex. Europe: Germany, 
France, Hungary, Roumania, Italy. 
Asia: Turkestan, Indo-China. 

The number of spiral ridges 'Aamm 

in the pharynx seems to vary r,^, ,.^Ari^« ..r«m«^. p«Mr*o, -d ^ 

both with the sex and among body otlemale.vtewad from leltdde. •..uiUK 

different individuals of the same T'^'^^^llf^'^'v^r^^.I^ 

(er- p., tenoma] papula. X 1«1- (Ongtoal.) 

sex. In the specimen figured, a 

female (fig. 1), there are four separate ridges, the usual number for 
females. Males have, as a rule, but three spirals. Railliet and Henry 
(1911b) mention 2 to 3 spiral ridges for males and 4 to 5 for females. 
The retractor muscles controlling the movements of the right 
spicule are a pair of narrow lamellar strips, lon^tudinally finely 
striated, asymmetrically twisted in the center, attached at the pos- 
terior end to the spicule and at the anterior end to the ventral side 



THE BOUNDWOBMB OF DOMESTIC SWINB. 



13 



of the body. The musclea are fully as long as the spicule they control 
(fig. 7). 

The Taa deferens appears as a tube of darker color than the intes- 
tine, about 130 /I in its average diameter, and extending throughout 
the posterior third of the body length. About 450 p. from its ter- 
minus it rapidly diminishes in diameter toward the cloaca, and in 
the specimen figured (iig. S) ia bent in 
the shape of the letter S. The seminal 
tube is very long and convoluted, re- 
semblii^ in appearance the ovaries of 
the female. Near the posterior end of 
the male the intestine, 123 /< wide, first 
crosses above the vas deferens toward 
the dorsum, then curvee underneath as 
it approaches the cloaca. Ite terminus 
was obscured by the organs lying above 
it. In the specimen figured (fig. 8) the 
sheath of the right spicule is much con- 
tracted and appears as a dark-colored 
bag too short to contain the entire 
spicule and within which the base of 

the spicule 

may be 

dimly 

seen. The 
. ventral 

surface of 

f the male 

' '■ in the re- 



F:o. i 



Ariuama tmnfi^ina 



r>l 



Tlnr of middle of bod;o[ female. 
■nUclor uterus: IM.. iDtestiDe: }. \a., 
JoDcUoii (i( the uUri; 1. c. v., laWnl 
cutlculAr wln^; p. lU., pooleTior ulerus; 
V. valval M.. vsglDB. x U. (Original.) 



mediately 
anterior of 
the bursa 
is f u r - 
nished with 7 to 8 parallel longitudinal 

, , cuticular ridges divided transversely 

\OjX- i^to serrations. This structure, modi- 

pm. t.—Ariutwm ttauttutim. LMerai fications of whtch are Seen in many 

vi.wot«nreino«d^n»rvi[rtuwi nematodes, including Physocephalua 

tat., amixTo'; A., riteiL x i,uo! sexoUUvs, prohably assiste in maintain- 

(OrKbnL) j^g tjjg position of the male in copida- 

tion, as suggested by Ciurea (1911). The anus is partially encircled 

by a rim of thickened cuticle, the outer edge of which is ornamented 

with serrated cuticular projections. This cuticular thickening 

extends along the posterior and left sides of the anus, forming about 



14 THE BOUNDWORMS OP DOMESTIC SWINE. 

two-thirds of a complete circle. Tlie thickened cuticle seems to 

project downward into the body (fig. 2). 
Ciurea (1911) depicts 10 tactile papillte located on the ventral 

Btu^ace of the body of the male, close to the tip of the tail. These 
could not be seen in the specimens studied 
by the writer. The rectum (fig. 4) of the 
female is about 80 /i in maximum width and 
nearly aa long as the distance from the anus 
to the tip of the tail. la the r^on immedi- 
ately posterior of the anus several fine lines 




7.—ATdutnna itniiinliiltt. 
Short iplcult niUi reiracUr 
miBclss viewed from right ride. 
rO. m., recraclor diusoIh; i. ip., 
abort spicule. X BD. (Orleliul-) 

can be seen beneath the 
cuticle, converging toward 
the baseof the anus. These 
are probably muscle fibers 
controlling the rectum, and 
are seen in the females of 
many nematodes. A pair 
of papillte close to the tip 
of the tail extend laterally 
to the edges of the caudal 
cuticle on the ventral 
side. 

In a cross section of Ar- 
duenna atrongylina (fig. 9 of 
the present article), Ciurea 
(1911) shows that the in- 
terior of the lateral wing 
is filled with a substance 
shaped like the letter V 
when viewed in this posi- 
tion. In its reaction to 
hematoxylin it resembles the thickened wall of the pharynx. 

The same drawing (fig. 9) also shows that the vagina first passes 
between the cuticle and muscular wall as it crosses the body to ex- 
tend along the right side. In several of the specimens examined by 
him, Ciurea (1911) noticed a drop of hardened cement at the opening 



Slomm. 

K3. g.— .IrAunna ilrangjiUna, Posterior end ol body ot 
male, vlen-ed Iroin left side, d,, cloaca; Jbi., InteMlne; 
I. b, IB., left bursal wlni;; po. p., postuial psplllBii pr. p., 
ptearuU pnpilte; pr. r. , pfriknal Hng; (t.r.(p.,Bbealhollaiv 
epiFUIe; all. i. ip., ahtaUi of short spicule; i. ip., short spi- 
cule; T.tt/.,naiielenat; (i.r.e.,ventnltUg«otlligcuClde, 
X 5S. (Orlglul.) 



THE BOUNDWOBMS OF DOMESTIC SWINE. 



15 



of the Yxilva, and in cross section it was seen that the same material 

filled the terminus of the vagina. This material was not seen in 

any of tiie specimens examined by the present writer.' 
The vagina (fig. 5) extends first transTersely under the uteri and 

intestine; then leading above these organs it continues posterioiiy 

and parallel with the intestine (except 

for an S-shaped bend near its middle) 

along the right side imtil it reaches 

the juDctJon of the uteri. 
Oneof theuteri,commencingat the 

end of the vagina, extends posteriorly 

and dorsally without convolulioiis 

(except for an S-shaped bend 875 p 

from its vaginal end) until it reaches 

a point 3.6 mm. from its union with 
the vagina. 
Hereitmakes 

an abru p t ^la. t.-Ajiunim 1ronetll«>. Cna »«ltn 
turn, runs throngh body oIfein«Je in the region ot the 
.1 . . TulTm. M. w., body wall 

DaCK anten- „tg^._ i^,_ Intotlne; W.. 1 

orly and ven- 
trally, paral- 
lel with its dorsal limb, until its outUne is 
lost to view beneath the ma^ of eggs distend- 
ing both uteri and filling the body cavity 
from the end of the esophagus to within a 
short distance of the anus, greatly obscuring 
the outlines of the oigans. Throughout its 
visible length this uterus is of nearly uniform 
diameter, about 95 /i. The distal ends of the 
two uteri are at opposite extremities of the 
worm; the uterus that first extends poste- 
riorly ends anteriorly at a point 613 /t anterior 
of the base of the esophagus in a long con- 
voluted ovary crowded into the narrow space 
between the esophagus and the lateral mus- 
cular wall. The other uterus, running in a 
similar but reverse direction from the uterus 
just described, turns first anteriorly for about 3.5 mm., then posteriorly, 
ending at a point about 875 /< from the tip of the tail. The diameter 
of the posterior uterus, like that of the anterior uterus, is nearly 




ia.,viglu. Enlaced. (AnvCtnrea,IBll. 



ii l> not, ban 

juniUiiiiun ths vulva at vlUcti i 
ibia in tloattal but «hleb oould thsUy be removed by m ne 
Tsd » Itrmly welded Id oopDiMton tbat bot tlcobol did i 
U> Imifble tnntkm with ■ needle or loro^is. 



The Trlter bu collected many ipecl- 
113 oloeed by a plug o[ dark-red nenlion 
■lie. Hpeclmeos of thli parasite have been 
at cause their aeparatkiD and tbey yitfdad 



16 



THE BOUNDWOKMS OF DOMESTIC SWINE. 



uniform^ about 95 /i. The posterior ovary, much convoluted, fills 
most of the space between the anus and the terminus of the posterior 
uterus (fig. 4). The ovaries are long filiform tubes, 34 /t in diameter 
in their narrowest part. The thick-shelled eggs are covered with a 
thin irregular membrane resembling the albuminous membrane of an 
ascarid egg. Under high power a faint line at either pole can be 
seen running transversely through the thickness of the shell, sug- 
gesting an opercidum. The embryo is siurounded by a thin envel- 
ope, differentiated from the shell by its greater translucence and 
lack of granulation (fig. 6). Most of the eggs in the uterus contain 
well-developed embryos, but a few near the ovaries appear in the 

morula stage. The shell, including 
the translucent membrane surround- 
ing the embryo, is 4 ft thick, the 
embryo occupying a space 11 /* by 
24 fi. 

The general appearance of the two 
sexes is represented in figures 10 
and 11. 

The first specimens of Arduenna 
strongylina were collected by Bremser 
and figured by him in his Icones 
Helminthum (Bremser 1 824c) . They 
were first described, however, by 
Rudolphi (1819a, p. 237). His de- 
scription may be freely translated as 
follows : 

Head slender, continuous, mouth orbicular, 
body somewhat attenuated anteriorly, tail of 
male coiled either in a single spiral or in a 
spiral and a half. A broad wing extending 
on either side of the tail. Spicule very long. 
Apex of the tail very short, naked. Apex of 
the tail of the female depressed, straight, 
subacute. 

In a preUminary note Rudolphi (1819a) gives the measurement of 
the males as about 5 Unes long (»10.6 mm.) and the females as 7 
lines long (=14.9 mm.). 

Gurlt (1831a) is the first on record to collect the worm from domes- 
tic swine. His description of the anatomy of Spiroptera strongylirva 
follows Rudolphi's, but contains also the statement that the vulva 
is situated a short distance in front of the anus. He describes the 
mouth as smooth, without papillas. Subsequently (Giu*lt, 1847a) he 
added to his description a note on the anatomy of the pharynx, the 
first reference to this structure, which he describes as banded by two 
spiral muscles (a misinterpretation of the spiral chitinous ridges of 




Fio. 11.— il rdtt^iifui ttrongyUfM, Oeneral view 
of body of female from left side, a., anus; 
ut., uterus; v., location of viilva. X 7.5. 
(Original.) 



THE BOUNDWOBMS OP DOMESTIC SWINE. 17 

the pharynx) running the length of the esophagus in opposite direc- 
tions (fig. 12). 

Mo]in (1860b) describes the Tulva as situated posteriorly, and 
gives the following measurements: Males, 11 to 15 mm; females, 15 
to 23 mm, which figures agree- closely with the writer's measurements 
of Ardueniia atrorigylina. 

Schneider (1866a) reexamining Rudolphi's ma- 
terial, gives a correct drawing of the bursa of 
Arduenna strongylina, showing 5 pairs of papillae, / 
of which one pair is postanal, and describes the / ' 
anus as surrounded fwisterioriy by a crown of 
serrated cuticular prominences (%. 13). His 
description, however, does not in all respects 
agree with his drawing, as he states that there , 

are 6 pairs of papiUse while the drawing shows 
only 5 pairs. His description is also in error in 
regard to the position of the vulva, which he ^°- ^3.~Aiautnna inmer- 

. ., 1- 1 - , -.1 u™. Cephftllo ODd, «., 

describes as directly m front of the anus. mouth; p»„ pharynx. 

Von Linstow (1879b) states that the two Eaiaiged. {Aftar ourii. 
spicules measure respectively 0.72 and 0.26 mm. 
and that the mouth is surrounded with 6 round papiUse curved for- 
ward (fig. 14). His drawing shows the pharynx with a series of 
parallel ridges instead of a spiral, A comparison of his drawing (fig, 
14) with the anterior end of Pkygocephalus sexaiattis (fig. 15) gives 
rise to the suspicion that Yon Linstow has mistaken this species for 
Arduemia atrongylina, an opinion first expressed by RaiUiet and 
Henry (1911b). 

Zuero (1882a) is the first to men- 
tion the narrow lateral wing, extend- 
.am X--- — ing ion^tudinally along one side of 

the body. He describes it, however, 
as being in a median position. As 
has been shown, it extends along the 
left side only. 

Stossich (1897b) states that the long 

no. ia.-^rJu«wa KnmnifM. Bom of spicule is three times the length of the 

mde, ventiBl view. c(., cloaca; po. p., l,-. .■ -j.it-. 

posiwiai papUini pr, p., preanai pBpiii»; short Spicule, a latio evidently denved 

pr. r.. pvfuui ring. Eoiaijed. (Afiar fpQni Von Luistow's (1879b) meas- 

actureldBT, UMa, p. 101.) 

urements. 

At a meeting of the Helminthological Society of Washington, the 

writer (Foster, 1911) presented a note on Spiroptera strongylina in 

which he pointed out the differences between the anatomical features 

of specimens tentatively identified by him as Spifoptera stnmgylina 

MMS"— BuU. 16ft-12 3 




18 THE ROUNDWORMS OF DOMESTIC 8WINE. 

and the descriptions of this ajiecies by European observere. As no 
European specimens were at hand with which to compare the speci- 
mens collected in this country, it was concluded either that the 
American form represented a 
distinct species or else the de- 
scriptions of European writers 
were in error in some important 
details. In order to determine 
which of the two alternatives 
- was correct, specimens collected 

*^ in the United States were for- 

warded to Prof, von Linstow for 
comparison with specimens col- 
Fia.w.-P).Ho«pi»J"«^..te^. i*<«^viaw„f ^^-ted m Europe, and other 
ceptuucsnd. loA. p., labial pupuige; p».,pbar7Dx. European helminthologists Were 

Entarged. (AfUrVonUn,tow,187Bb,ri.V,flg.lIO ^y^^ j^^. specimens of SpiTOp- 

iera sirongylina. The specimens sent to Von Linstow were considered 
by him to be a different species from Spiroptera strongylina. There 
is, however, no question that certain European specimens recently 
received from Prof, Gedoelst, of Brussels, are specifically identical 
with the American 
form, nor can it be 
doubted that the form 
taken by Railliet and 
Henry (1911b) as 
Spiroptera strongylina 
is the same as the 
American form. 

In regard to the 
length of the spicules 
of Arduenna strongy- 
lina, the writer's ob- 
servations are not in 
accord with those of 
Ciurea(1911). Meas- 
urements of the spic- 
ules of over 35 males I , ^ ,. . , f 
made with the aid of a 
camera lucida and 
stage micrometer 
show that the long 
spicule varies between2.24 and2.95 mm. in length, while the short spic- 
ule is between 457 and 619 ji in length. The corresponding measure- 
ments given by Ciurea are, long spicule, 977 /i; short spicule, 221 ju. 
The measurements given by Railliet and Henry (19nb) are, long 



lomm. 



THE ROUNDWORMS OF DOMESTIC SWINE. 19 

spicule, 2.75 to 2.9 mm.; short spicule, 600 to 570 /£, thus confirming 
the present writer's observations. 

Arduenna strongylina, considered a rare parasite by Dujardin 
(1845a), Neumann (1892a), and Railliet (1893a), is now known to 
have a wide range. In this country at least it is very common, as 
will be shown later. In Europe it has been collected from the wild 
boar by Bremser (Rudolphi, 1819a) in Germany, and is reported by 
Dujardin (1845a) in Austria, and by Railliet and Henry (1911b) in 
France from the same host. It has been reported for domestic swine 
in Germany (Gurlt, 1831a), Hungary (Von R&tz, 1899d), Italy 
(Piana, 1897e), and Roumania (Ciurea, 1911). Most helmintholo- 
gists, following the older writers, state that the parasite is rare and 
occurs somewhat more commonly in the wild boar than in domestic 
swine. Dujardin (1845a) states that ''out of 19 wild boars dissected 
at the museum of Vienna, only 2 had this worm in the stomach." In 
Roumania, Ciurea found it in 9 out of 72 healthy swine, between 1 
and 27 specimens being found in a single host. Outside of Europe it 
has been reported by Von Ldnstow (1886c) from Turkestan, and by 
Railliet and Henry (1911b) from Annam Province, Indo-China. 
Some doubt, however, may be expressed regarding the identity of the 
parasite reported by Von Linstow (1886c) since, as has been shown. 
Von Linstow (1879b) has apparently confused PhysocepTudiis sexalatvs 
with Arduenna strongylina. The references to this parasite in tKe 
United States will be considered in detail in another part of the paper. 
Judging from its abundance in the United States, it seems not 
improbable that a careful examination of hogs' stomachs in European 
slaughterhouses would show a more widespread infection than 
hitherto reported. The specimens received by this bureau from 
Gedoelst were unaccompanied with any data giving the host or 
locality. Doubtless many veterinary schools and colleges throughout 
Europe contain specimens both of this parasite and of Physocephalus 
sexalatus which, like the specimens received from Gedoelst, have 
never been reported in the literature. 

An examination of the literature reveals only two authentic hosts 
for Arduen/na strongylina, namely, the European wild boar and 
domestic swine, although most writers subsequent to Diesing (1851a) 
have included the peccary in their lists of hosts. 

Diesing (1851a) identified as Spiroptera strongylina sonie specimens 
of worms in the Vienna museum collected by Natterer in Brazil, 
April 24, 1826, from the stomach of the white-lipped peccary (Dico- 
iyles laMatus) and labeled Spiroptera suis lahiati. As a result of his 
identification he (Diesing, 1851a) eidded Dicotyles alhirostris {^Dico- 
iyles laJnatus Cuv.)* to the previously known hosts of Spiroptera 

1 Dr. H. W. Henshaw, Chief of the Bureau of Biological Survey of the United States Department of 
Agriculture, In reply to a letter regarding the synonymy of Dkotylea labiatiu, states (Feb. 24, 1911) that, 
aooordtaig to Dr. J. A. AUen, of his bureau, Dkotyla UMaiut and oRnrottris are synonyms, labkUut baying 
praferaice as being the older term, the ooirect name, however, being Tayattu pecari Fischer. 



20 



THE BODNDWOBMS OF DOHEBTIC SWINE. 



strongylina. The specimens were subsequeoUy studied by Molin 
(1860b), recognized as a new species, and named bj him Spiroptera 
sexalata. Later helminthologists, although accepting Molin's species, 
have continued to include Dicotyles laMatua among the hosts reported 
for Arditenna strongylina, apparently ignoring the fact that M^Iin's 
(1860b) correction of Diesing's (1851a) identification eliminates the 
peccary as a host of Arduenna atrcyn- 
gylina, since this species has never 
been reported in the peccary except by 
Diesing (1851a). Stossich (1897b) ap- 
parently considered Dicotyles aibiro- 
stTis andi>. labiatits as separate species, 
lis ting under the formeT Spiroptera atrorir 
gylina and under the latter the para- 
sites collected by Nattererfrom the pec- 
cary and described by Molin (1860b). 
The stomach appears to be the 
normal location for Arduenna strongyliim; Yon R4tz (1899d), how- 
ever, reports its^bccurrence in the small intestine, 

Aiduenna dmUU (Von Linstow, 1904) Railliet and Henry, 1911. 
Von Linstow's {I904f) description of this species is as follows: 
Cuticula finely annulated. The mouth leade int« a pharynx 0.11 mm. long. ltd 
entrance ia armed with a dorsal and a ventral tooth; the mouth ia a tranisverse slit, the 
bonier of which dhows both an- 
teriorly and poeteiiorly, three 
notchee with papilte (fig. 16). 



Fia. lli,—ATianna intala. Medlao view 
of cephallo end. ph., phoryrix; t. b. c, 
teetb ol tbe buccal capsule. Enluged. 
(Aller Von Linstow, IWMt, PI. I, flg. fi.) 



of the 



The esophagus n: 

entire length and presents a spiral 
musculature. In a young worm 
14.6 mm. loug, the nerve ring 
surrounds the esophagus 2.64 mm. 
from the head end, and the excre- 
tory pore opena at a point situated 
0.31 mm. behind it. The male 
(25 mm. long by 0.79 mm. broad) 
has a closely involuted tail which 
reeembles that of SpiropUra 
itrongylina. The spiculee are re- 
spectively 0.35 and 0.92 mm. long, 
the shorter one bearing at its end 
a barb. Immediately anterior of 
the anus on each side there are four preanal papilla situated close together; behind 
it there is one papilla. All have bng stalks. The anus is surrounded by a broad 
ring, notched externally; the bursa shows longitudinal rows of oval scales. (Fig. 17), 
The female grows to a length of 55 mm. with a width of 1.10 mm. The short conical 
tail is curved over the back; the vulva is placed far behind the middle and divides the 
body in the ratio of 70 to 23. The eggs are small, thick shelled, and cylindrical, meas- 
uring 0.039 by 0.017 mm. 



Fio. 17.— j4iduniiM ifUata. Bum ol male, Tontnl view. 
CI., dOBOa: L b. u., left buraal wing; I. tp., long splcuk; 
jm. p., posUnat paplUn; pr. p., preanal papUlfB; pr. r., 
pprianal ling. Enlarged. (After Von Linatow, IMXf, PI. 
I, flg. 7.) 



THE ROUNDWOBMS OF DOMESTIC SWINE. 21 

The specimens described by Von Linstow were from the stomach 
of Sii8 cristatus at Chilaw, Ceylon, and are deposited in the museum 
of Colombo. Railliet and Henry (1911b) identify with Von Linstow's 
(1904f) Spiroptera dentata certain parasites collected from the stomachs 
of pigs slaughtered at Hu6, Annam Province, Indo-China, and include 
them in the genus Arduenna. The specimens examined by Railliet 
and Henry (1911b) differ, however, from Von Linstow's (1904f) de- 
scription in the position of the vulva and the length of the spicules. 
According to the former authorities, the position of the vulva is diffi- 
cult to observe, but the spicules measure 3.75 to 4.23 mm., and 640 to 
650 /£, respectively. 

The principal differences between Arduenna dentata and Arduenna 
strongylina are the greater size of the former and the fact that the 
chitinous ring surrounding the cloacal opening, described lovArduennxi 
strongylina, forms an almost complete circle in the case of Arduenna 
dentata, while in Arduenn^i strongylina it includes only the posterior 
and left sides. Railliet and Henry's measurements for Arduenna 
derUata ELTe: Males: 25 to 35 mm. long by 700 to 800 /u broad; females: 
40 to 55 mm. long by 1.1 to 1.2 mm. broad. 

Genus PHYSOCEPHALUS Diesing, 1861. 

Genebic diagnosis. — ^Filariidae: Body elongated, subcylindrical, slightly tapering 
anteriorly. Head marked off from the rest of the body by a cuticular inflation ending 
abruptly in a circular line a short distance anterior of the posterior end of the pharynx. 
Extending from the base of the cuticular inflation to about the middle of the body 
are 6 lateral cuticular wings, 3 on each side, the middle wing of each 3 being broader 
than the other two. Mouth with 2 trilobed lips, with a rounded papilla on each lobe, 
and leading into an inconspicuous buccal capsule without teeth. Pharynx relatively 
long and broad, marked by prominent ridges forming both spirals and simple rings, 
and extending the length of the pharynx on the inside. Tail of the male twisted 
spirally, furnished with a narrow symmetrical bursa supported by four pairs of preanal 
papilke. Spicules long and unequal, the left spicule about five times the length of 
the right spicule. Vulva somewhat posterior of the middle of the body; egga smooth, 
with thick shells, containing well-developed embryos at the moment of oviposition. 
Endoparasitic in the stomach of suidae. 

Type species. — Physocephalus seoxdatus (Molin, 1860) Diesing, 1861. 

Physocephaltts sexalatus (Molin, 1860) Diesing, 1861. 

1860: Spiroptera sexalaia Molin, 1860b, p. 957. 

1860: Spiroptera strongylina suis lahiati: Molin, 1860b, p. 957 

(Museum label). 
1861: Physocephalus sexakUus (Molin) Diesing, 1861a, p. 686. 

Specific diagnosis. — Physocephalus: Head about 60 ju in diameter at the anterior 
end, furnished with 2 tiilobed lips, each lobe being ornamented with a thick, rounded 
chitinous papilla (fig. 15). The cuticle of the head, extending from the mouth to a 
point 232 n from the anterior end, is more or less inflated. Pharynx cylindrical, 263 



22 



THE HOUNDWORMS OF DOMESTIC SWINE. 



to 315 p long by 53 p wide, f iiniiched with a spiral band which usually brcaka up into 

eeparat« rings in the middle of its rourae and resuinea tho spiral toward the posterior 

end. The number of turns to thB spiral varies between 21 and 25. There ia a cervical 

papilla on the leftside, 281/1 from the anterior end. The excretory pore opens on the 

right Bide, 526 p from the anterior end. The lateral cuticular wings, 3 on each aide, 

commencing at the base nf the cephalic cuticular inflation, extend posteriorly for a 

diatAQce about one-third of the body length. The middle wing of each three is 60 ;i 

wide at its middle, the point of 

^"^ greatest width. The other winga 

aie about half s» wide (fig. 18). 

ifol;, 6 to9mm. long, measured 
in aetraight line. Body nearly 
uniform in diameter, averaging 
263 p, and atlaining ita greatest 
width of 315 /I at the point of the 
greatest widlh of the Uteral 
wingB. The narrow bursal mem- 
branes, about half the width of 
the body, exl«nd from a point 
about 1,4 or 1.5 mm. from the 
t^ caudal extremity, to and includ- 

ing the bluntly pointed tip (fig. 
19). Caudal extremity twisted 
into afairly regular spiral, having 
usually three turns. Long spicule 
grooved on the ventral side, 2.1 
^ to 2.25 mm. in length,or fiveto 
six times the length of the short 
spicule, very slender, gradually 
a tapering to a fine needle point. 
Short spicule 300 to 350 ;i long, 
relatively broad at its base, sud- 
denly tapering to a fine point. 
The ventral surface of the short 
spicule is provided with a narrow 
wing extending nearly to the tip. 

I Bursa furnished with eight pairs 

ijQ^^ otpapilte(fig.20). Of these the 

1^^ four pairs of preanal papill« are 
p., long and stalked; the postanal 
P; papilliP, close to the tip of the tail, 
™ are very small, with short stalks. 
Female 13 to 19 mm. long, 
averse about 16 or 17 mm. Maximum width, 333 to 450 p in the region directly 
anterior of the anus. The body rapidly increases in diameter from the anterior 
end to the r^ion of greateet width of the lateral cuticular wings. At this point 
the diameter is nearly as great as in the region of tho anus. It then rapidly 
diminishes 1o half as much at the end of th& fiist third of tbe body; then slowly 
increasing, it reaches a maximum near the anus and abruptly diminishes, the 
body ending in a blunt point furnished with a mucronate tip. Anus 120 p from the 
caudal end, 50;t in diameter (fig. 21). Vulva posterior of the middle, 35 p in diam- 
eter, dividing the body in the ratio of 9 to 8. The vagina extends posteriorly (fig. 22). 
Uterus bilobed, the ovaripa lying at opposite extremities. Eggs 34 by 15 ;i, slightly 
flattened at the poles. Embryo well developed before oviposition {fig, 23). 



Fic 13. — FhftoctpAaliu taalatut. IXjrsa] vLc 
end of body. t. cur. Inf., cephalic cuticular I 
c«rv{ca] papilla; rf.,flsopbB£U9; n. p.,excmtoT 
labial paplllff'; I. e. w., IslersI cuticular «Ibi 
rln;; pft., pharynx. X lAO. (Orighul.) 



THE ROUNDWORMS OF DOMESTIC SWINE. 23 

Hosts. — White-lipped peccarj' (Tayaxtu peeari), wild boat (Sui Km/a /era), 
domestic htg {Sug tcro/a domestica). 

Location. — Stomach and smaJl iiifoMtine. 

Localities coLLEfrrED, — Brazil; Ilaly; Germany; Roumania; Madagascar; Indo- 
ChiDa; United States, east, middle, and soHthwest. (Apparently same rauge aa 
Ardumna tlrongylina.) 

Aa already mentioned, Physoceph- 
ahis aexalatua was first identified 
as Spiroptera strongylina by Diesing 
(1851a). Molin (1860b) subse- 
quently described the specimens 
under tbe name Spiroptera sexahia, 
and the following year Diesing 
(1861a,) placed the species in a new 
genus Physocephalua, of which it is 
the type and only species. The 
spei'imens studied both by Molin 
and Diesing were collected by Nat- 
tererfrom the white-lipped peccary 
in Brazil, April 24, 1826, and depos- 
ited in the Vienna Museum labeled 
Spiroptera strongylina suis labiali. 

Molin's (1 $60b) somewhat meager 
description sums up the saUent ™. 

points (the lateral wings and spiral 
tail of the male) by which Pky- 
aocephalus sexalatus may be recog- 
nized. He describes tlie males as 
7 mm. long and 2 mm. wide, and 
the females as 9 to 13 mm. long and 
3 to 5 mm. wide. The mouth is de- 
scribed as bilobed, each lobe with a 
three-cornered margin. Diesing 
(1861a), although creating a new 
genuff from Molin's species, adds 
little to our knowledge of its anat^ 
omy. 

It has already been noted that 
Von Linstow (1879b) has appar- Fio,is.-p*jf< 
ently mistaken Phyaocephatia sexa- " " " 
lotus for Arduenna stnmfftflina. 
His measurements of the spicules 
(0.72 mm. for the long and 0.26 mm. for the sliort spicule) are, how- 
ever, much too short for A. strongylina and also for P. sextdaius. 

Von Drasche (1884a), in his reexamination of Diesing's and Molin'f 
specimens, made a careful study of the bursal papilJse and the struc- 



lataius. Posterior ond 
otbodyof male. 6. u>., bursal wing; cl.,c\oee»\ 
I. tp.Jong spli^ule; pr. p., praanal papillse; <. 
jp., short spicule; P. r. e., veotral ridge ol the 
cuticle. X SO. {Original.) 



24 THE ROUNDWORMS OF DOMESTIC SWINE. 

ture of the lateral wings, illustrating tlie description with drawings, 
which were of great value to the present writer in verifying his iden- 
tification. In common with Railliet and Henry (1911b) the present 
writer was unable to find the pair of papillre depicted by Von Drasche 
(18S4a, fig. 24 of this article) close to tlie edge of the anus. Ciurea 
(1912), however, depicts a pair of papillse immediately posterior of 
the anus, which he states are not easily seen. At the extreme tip of 
the tail Von Drasche (fig. 24) shows three pairs of minute apparently 
sessile papillse. In reality there are four pairs of minute staked 
papillee at this point. These appeared very clearly with a high 



Fio. 30.—PkftBaiiAabH malatui. Bursa of male, viewed from left side, el., doacs; 1. b. k,, left buml 
wing; t. ip., lung splculei pa. p., postanal paplUs;; pr, p., preaoBl p*plUx: r. b. w., right buisal wing; 
(t.t.ip.,sheatli of short spiouK >.>p.,ahort spicule; c. ii>.,vaDtral wing of short spicule. X ICO. (Orig- 

power in mounts presenting a somewhat lateral view (fig, 20). The 
structure at the tip of the tail with its rows of minute papillce is not 
unlike that depicted by Ciurea (1911) for the bursa of Arduenna 
strongyUna. As already stated, however, no such structure was seen 
by the present writer on the bursa of this species. In a cross section 
of P. sexalaius (fig. 25) Von Drasche shows that the projecting cuticle 
forming the lateral wings has corresponding depressions inward. 

Stossich's (1897b) description of P. sexalatys follows that of Molin 
and Von Drasche. Piana (1897e), in an article on Sinwndsia puTO- 
doxa, mentions finding two other species of nematodes in the same 
bottle containing the specimens of Siraondsia. He identified these 
as being Spiropiera stroTigylina and Pkysocepkalus sexalatua. .These 
specimens were from an Italian pig. 



THE ROUNDWOBMS OF DOMESTIC SWINE. 25 

Railliet and Henry's (1911b) description of Physocephdlus aexa- 
lotus is based on specimens collected from a hog slaughtered at Hu6, 
Indo-Cbina. These authors also report having observed it in material 
from Madagascar in 1905. 

Ciurea (1912) reported Spiroptera aexaiata in domestic swine 
alau^tered at Piatra Neamtz, Roumania, in 1910. Five out of 72 
healthy swine were infested with from one to -thirty of these para- 



BndotbodrofIBinal8,™nti»lTlew. i,,!!!)!^: ' U-— _ 

a.M.uMrlOTuMnisKM., Intestine; l.a.U., lOnHII. 

loopotuilariiirutaniii: iw.,o™ry; p.u(.,po»- f,a, Zi.-PkrxKipluiltu italaitu. Vmtnl viev o( body of h 
UrkoruMnu. X JO. (Otiglnsl.) nu)* In the n^too of Iha vuIvb. Inf., Inlestina; ut., ulvma 

c, vulva; us., vagina, x 95. (Original.) 

sites in the stomach. In three cases they were found associated 
with Arduenna atrongylina, and once with Gnatkostoma Jiiapidum. 
In this latter case the parasites were found in the ulcer caused by 
Q. hispidum. The worms were partially or entirely buried in the 
mucosa, but no lesions were attributed to them. Ciurea's (1912) 
description and drawings of PJiysocepkalua aexalatua agree in most 
respects with the present writer's observations, the few differences 
being noted in the course of this article. 



26 THE ROUNDWORMS OF DOMESTIC SWINE. 

Seurat (1912) reports finding several hundred specimem of Spi- 
roptera aexalata partially buried in the mucosa of the stomach of an 
— ass slaughtered in Algeria during July, 1911. 

A subsequent examination of the fourth 
stomachs of six dromedaries revealed numer- 
(j, ous specimens of this species hidden between 
the folds of the mucosa, associated with 
rtO. Haemonchus coniortus. While the description 
of t)ie specimens agrees in general with the 
present writer's observations, the measure- 
ments are all somewhat larger. The width 
of the middle lateral wing (110 to 120 [t as 
given by Seurat) is over twice as great as 
that given hy tlie present writer, while the 
vulva is described as located at the anterior 
third of the body, instead of sUghtly posterior 
of tlie middle, as described by Railliet and 
Henry (1911b), Ciurea (1912), and Foster 
. jj-)i t (1912) (the present article). 

' ^A^ Seurat (1912) also found in the dromedary 

Fig. 23.— Pitaoavhalut uiaialtu. , i p i ■ i i ■ i ■ , 

LnierBi view oi egg removeu another form which ho cousidcrs as a variety 
''ibi^'"**'"*^ "T"- 't' "^^ designates as var. criaUUa. This form 
embryo; ik., sbeii. X i,»5o! is distinguished from the typical species by 
(Original.) havii^ four longitudinal crests on the head, 

formed by four cuticular folds, and having four cuticular spines in 

the mouth cavity. In this variety the position of the vulva is not 

constant, but varies from the posterior 

third of the body to an anterior position. 
As Seurat'a (1912) measurements of 

PhyaocepJuilus sexaUUua differ considerably 

from the present writer's, and as the species 

has hitherto been reported only in the 

Suidfe, it would seem desirable to reserve 

an opinion until his statements can be 

confirmed. 

The stomach is the normal location for 

Physocephalne aexalatus. . Von Linstow 

(1879b) reports Fihria strongylina as col- p,,, u.-pi,tii,c,pkaiu, taaiMi. 

lected from the small intestine of a hog Bursaofmaie.vBntrniTiBw. <«i.p., 

L r\ xr Ti - t a^ J.X i. * i, ndaoal papQla; 1. 6. ic., lett bursal 

by Dr. V. Hering, of otuttgart. As has n-mg: r«p.,iong!piciii«; p<i.p.,port- 
been shown, Von Linstow apparenUy con- "''"'i;'^l'^";;Sr°'"**^lllS 

' ^^ . 1 » T r.o-K..rieQtDursalwtag;»,»p., Short 

fused PhySOCephalUS SeXOtOiuS with Ardu- spicule. X280. (AtWrVon Draach*, ^ 

enna stTongylina; it would seem there- ' " ' 

fore, that P. sexahius may occasionally occur in the small intestine. 
In most specimens examined by the autlior the cuticle of tlie head 
appears as shown in fig. 18, which is closely similar to the form 



THE ROUNDWORMS OF DOMESTIC SWINE. 



27 



/c^ 




TlQ.25.^Physoccphalutsexalatus. Cross 
section through anterior part of body. 
bd. w., body wall; I. c. w., lateral cu- 
tlcular wings. X 280. (After Von 
Drasche, 1884a, PI. XIV, flg. 4.) 



e.eui3it^i 



depicted by Von Drasche (1884a). In about 20 per cent of the 
specimens examined, however, the cuticle, from the lips to the 
beginning of the lateral cuticular wings, 
is inflated into two hemispherical vesicu- 
lar wings (fig. 26). This second form is 
not mentioned by Molin (1860b) or Von 
Drasche (1884a), but possibly may be 
referred to by Diesing (1861a) in the ex- 
pression ^^epidermide in buUam inflata 
tunicatum'' in his description of the 
genus Physocephalus. 

The pharynx of P. sexalcUus is about 
three times as long and twice as broad as 
that of ArdiLenna strongylinaj and this, 
together with the lateral wings character- 
istic of the genus, are the salient points in 
distinguishing the females of the two genera. At first sight the 
ridges of the pharynx appear to form separate rings and are so 

described by Von Linstow 
(1879b and in litt) . By careful 
focusing, however, it is seen 
that these ridges form a simple 
spiral at the anterior end of the 
pharynx and after making four 
or five turns split up into sepa- 
rate rings. At the posterior 
end of the pharynx they are 
again joined into a simple spiral 
(fig. 18) . The final loop of the 
anterior spiral forms the first 
ring of the series, and the begin- 
ning of the posterior spiral takes 
its origin from the lower part of 
the last ring. The number of 
loops to the spirals and the num- 
ber of separate rings is subj ect to 
considerable variation. A rather 
extreme case is seen in fig. 27. 
Here the first spiral has five 
loops followed by a detached 
ring. This in turn is followed 
by a spiral of four loops, after 
which are two detached rings. 
The final spiral consists of 11 
continuous loops. In every case, however, so far as observed, the ridges 
form both spirals and rings, commencing and ending with a spiral, and 




Fio. 26.—Pkptocephdluasexdlaitt8. Ventral view of body 
of female, a. , anas; e. cut. inf. , cervical cuticnlar Infla- 
tion; I. e. w.f lateral cuticular wings; v., vulva. X 7. 
(Original.) 



eetit 



28 THE BOUNDWOHMB OF DOMESTIC SWIJTE. 

not a series of parallel bands, as described by Von Linatow (1879b), or a 

continuous spiral, aa described by Von Drasche (1884a), R&illiet and 

Henry (1911b), and Ciurea (1912). 
RaiUiet and Henry (1911b) mention two asymmetrical cervical 

papillaa, the right papilla being 220 /i and the left 420 p. from the 
anterior end. As seen by the present 
writer the left papilla has a broad 
base and a blunt point and pene- 
trates the cuticle 281 /i from the an- 
terior end, or a little anterior of the 
base of the cephalic inflation. The 
right papilla was not seen by the 
present writer, but on the right side, 
not far from the location of the papilla 
as given by Railliet and Henry 
(1911b), the excretory canal opens. 
The end of the canal is a slender 
tube penetrating the middle lateral 
wing and looking not unlike a long 
stalked papilla (fig. 18). Its true 
nature has been shown by Ciurea 
(1912), who made a cross section of 
the worm at this point. The lateral 
situation of the excretory pore is ap- 
parently unique among nematodes, 
the usual situation being ventral. 

The lateral cuticular wings unite 
just posterior of the base of the ce- 
phalic inflation (fig. 18). Here the 
cuticle forms an inverted pocket like 
the handle of a table drawer (fig. 27). 
The lateral cuticular wings are densely 
striated at the base, giving them a 
puckered appearance. Although the 
uticle of the entire body is striated, 
these striations appear more promi- 
nently on the lateral wings, particu- 
larly at their base, than elsewhere. 
The esophagus, about four-fifths of 

the length of the lateral wings, is densely striated transversely, 

with a very narrow lumen; nerve ring 439 ^ from the anterior end 

(fig. 18). The intestine is more or less convoluted throughout its 

course, especially posteriorly. 

The male (fig. 28) is about half the length of the female, but as 2 

to 3 mm. of the posterior end is twisted into a spiral, its apparent 

length is much shortened. 



LstenI 



Fia. m.—PkiHXtvt'aiut letoluiu 
vlen' ol anlerloi end ol body, 
cervlral cuticular Inflatioa; eat., cullcle; 
rt.. ewpbaeu]; n. p., txavVtrj pore; lot. 
p.,hblalpaplUte: 1. 1 
wings: n- r., Derra ring; pA., pbarTDX. 
X IM. (Orighul.) 



THE ROUNDWOBMS OF DOMESTIC SWINE. 



29 



The spiral of the caudal end of the male appeared in a few cases as 
a single coil like that of Arduenna gtrongylina. In other cases it con- 
sisted of an irregular double twist (fig. 28). .In the greater number 
of specimens examined, however, it formed a broad open spiral like 
a corkscrew (fig. 19). Comparing the spiral to the thread of a screw, 
and considering the tip of the tail as the point of the screw, the spiral 
resembles a left-handed screw with three (rarely four) threads; no 
cases were seen in which the spiral 
revolved in the opposite direction. 

The bursal wings are described 
as symmetrical by Railliet and 
Henry (1911b) and are so depicted 
by Von Drasche (1884a). The right 
wing is, however, a little longer than 
the left wing (fig. 19). Qurea (1912) 
considers that it is also narrower, 
but this statement could not be veri- 
fied by the present writer. Qurea 
(1912) states that the bursal wings 
extend throughout the twisted poi^ 
tion of the tail. As seen by the 
present writer they extend only about 
half this distance (fig. 19). The 
cuticle on the ventral side of the 
male (fig. 19), commencing at some 
distance anterior of the spiral, is 
marked with longitudinal striations 
intercepted by transverse lines, ap- 
pearing under high power as longi* 
tudinal folds of the cuticle separated 
by transverse ridges. A similar struc- 
ture has already been noted on the 
ventral surface of ArdiLeuTia strongy^ 
Una (fig. 2). As in most nematodes, 
the papill» are arranged symmetri- 
cally on either side of the median 
line. Their grouping and structure 
have already been discussed. 

The intestine is much convoluted, growing broader close to the 
cloaca. The vesicula seminalis occupies most of the body cavity in 
the posterior end, maintaining a fairly uniform diameter until it 
disappears dorsal of the intestine which conceals the ductus ejacu- 
latorius. The long convoluted testis which extends to the middle of 
the body presents no specific characteristic features. The anus is 




Imm. 



Fio. 2&.—'Php8oeephalU8 aexdlatua. General 
view of body of male. 6. , buna; et., eeopb- 
agus; «pf., spicules. X 23. (OriglDaL) 



30 THE BOUNDWORMS OF DOMESTIC SWINE. 

circular, like that of Arduenna strongylina, but not surrounded by a 
serrated ring. 

} The vulva (36 fi in diameter), as in Arduenna strongylina, appar- 
ently occupies a somewhat lateral rather than ventral position, open- 
ing toward the right side (fig. 22). It is situated just below the 
middle of the body, dividing the worm in the ratio of 9 to 8. Accord- 
ing to Ciurea (1912) the cuticle in the region of the vulva is marked 
with longitudinal thickenings which may interlock with the cuticular 
ridges on the ventral surface of the male, and thus assist in maintain- 
ing the position of the male in copulation. The vagina, extending 
posteriorly along the right side, is at first 50 ;£ in diameter, but gradu- 
ally broadens to 105 /£ at its posterior end, where it disappears from 
the ventral side, extending dorsal of a lobe of the uterus. The dis- 
tance from the vulva to this point is 976 jn. The wall of the vagina 
is relatively thick, composed of transverse muscle fibers. The lumen 
is 20 /£ in diameter. Eggs containing well-developed embryos 
ready to pass out could be seen in single file in the lumen of the 
vagina near the opening (fig. 22). Railliet and Henry (1911b) 
describe the vulva as opening posteriorly at the limit of the third 
and four fifths of the body. Von Linstow (in litt) places it somewhat 
posterior of the middle of the body, dividing the worm in the ratio 
of 10 to 9. 

The arrangement of the uteri and ovaries in the body of the female 
is, so far as could be seen, similar to that of Arduennu strongylina. 
The convoluted ovary of the posterior uterus occupies the caudal 
extremity of the worm, its terminus disappearing dorsal of the pos- 
terior uterus. A loop of the anterior uterus extends nearly to the 
caudal end. The exact length of the vagina was not determined. 
A loop of the posterior uterus, corresponding to the loop of the anterior 
uterus, lies underneath the anterior uterus and extends nearly to its 
terminus. The union of the vagina with the uteri was not seen, nor 
was the anterior ovary traced throughout its length. While neither 
uterus was followed throughout its entire length, the two termini, 
one posterior the other anterior, the posterior uterine loop, and the 
anterior loop, are all similar to the arrangement seen more clearly in 
Arduenna strongylina. 

Gurea (1912) depicts a pluglike protuberance at one of the poles 
of the eggs of PhysocepJialus sexalatus, which bears a superficial re- 
semblance to the operculum of a Trichuris egg, but does not penetrate 
the eggshell as in the latter case. This feature was not seen by the 
present writer; however, a faint transverse line could be seen at 
either pole (fig. 23), which apparently is the line of fissure along which 
the shell breaks when the embryo is Uberated. 



THE ROUNDWORMS OF DOMESTIC SWINE. 31 

COMPARISON OF PHYSOCEPHALU8 SEXALATUS AND ARDUENNA 

STRONGYLINA. 

The following comparison of appearances of Arduenna strongylina 
and Physocephalus sexalatus will assist in separating the two species 
without the aid of a magnifier. - 

Males, — ^Tail of Physocephalus sexalatus ending in a spiral, Ardu- 
enna strongylina ending in a single coU; Physocephalus sexalatus 
shorter and slenderer than Arduenna strongylina. 

Females. — Physocephalus sexalatus straight, or nearly so; speci- 
mens preserved in alcohol when lifted out of a petri dish with a 
needle bend sharply in the middle. Body slenderer than Arduenna 
strongylina, except toward the posterior end, which is thicker and 
blunter. 

Alcohol specimens of Arduenna strongylina are usually curved in a 
half circle. They are thicker in the" middle of the body than Physo- 
cephalus sexalatus and pointed at both ends. On being lifted with a 
needle they do not collapse like Physocephalus sexalatus, but maintain 
their crescentic shape. 

As has already been stated, MoUn (1860b) was the first to distin- 
guish this species from Arduenna stron^lina, with which it had been 
confused by Diesing (1851a). 'Besides the specimens from the white- 
lipped peccary, Molin (1860b) also found two females of this species 
in a bottle containing specimens of Arduenna stron^lina collected 
by Bremser from the stomach of the wild boar and deposited in the 
Vienna Museum. That it has only twice been reported in Europe 
in association with Arduenna strongylina is perhaps due to confusion 
of the two species, an error which appears to have occurred in at least 
one case (Von Linstow, 1879b). In the United States it has been 
found in nearly every case in which specimens of Arduenna strongylina 
have been collected. 

OTHER SPECIES REFERRED TO PHYSOCEPHALUS SEXALATUS. 

Two other worms have been thought by diflFerent writers to be possi- 
bly identical with Physocephalus sexalatus, viz, Simondsia paradoxa 
(Cobbold, 1864b) from Sus scrofa domestica and FHaria nitidvlans 
(Schneider, 1866a) from Tapiras americamis. 

Simondsia paradoxa was collected from the stomach of a German 
hog kept at Regent's Park, Ijondon, and was described by Cobbold 
(1864b). In a later work (1879b) Cobbold suggests the possibiUty 
of the worm being identical with Physocephalus sexalatus. The 
immensely hypertrophied uterus of Simondsia paradoxa, forming a 
rosette entirely covering the caudal end of the female, however, clearly 
differentiates this species from Physocephalus sexalaius. 



32 THE ROUNDWORMS OF DOMESTIC SWINE. 

In his description of Physocephdhis, Von Drasche (1884a) suggests 
the possibility that Schneider's (1866a) FHaria nitidulans may be 
identical with P. sexalatus. Both worms are characterized by three 
lateral wings on either side, and the caudal extremity of the males of 
both species are ahke in the number and arrangement of the papillae. 
The measurements of FUaria nitidulans (males 20 mm., females 32 
mm.) are, however, far in excess of the measurements for Phyao- 
cephalv^ sexalatua, and the position of the vulva of FUaria nitidulans 
is stated as ** directly above the anus," while the vulva of Physo- 
cephalus sexalatus is slightly posterior of the middle of the body. 
Ciurea (1912), who has recently reexamined Schneider's material, was 
unable to determine the location of the vulva of F. nitidulans. He 
gives, however, a sununary of the differences between FUaria nitidvr- 
lans and Physocephalus sexalatus, proving conclusively that they be- 
long to different species, although he considers that FUaria nitidulans 
should be included in the genus Physocephalus. Stossich (1897b), fol- 
lowing Von Drasche's (1884a) suggestion, considered the worms 
identical. He listed Tapirus americanus as a host of Physocephalus 
sexalatus and combined Molin's (1860b) measurements of P. sexalatus 
with Schneider's (1866a) measurements of FUaria nitidulans. 

DISTBIBimON OF ABDUBNNA STBQNaTLINA AND FHYSOGBPHA- 

LTJS SEXALATUS IN THE UNITED STATES. 

Of nine lots of Arduenna strongylina collected in various parts of 
the United States and now deposited in the helminthological collection 
of the Bureau of Animal Industry, only two have been found not to 
contain examples of Physocephalus sexalatus, and both of these lots 
contain only a few specimens. The distribution of Arduenna strongy- 
lina is therefore similar to that of Physocephalus sexalatus, since the 
latter species, according to the writer's experience, is practically always 
associated with the former. 

To determine the distribution of these parasites and the frequency 
of their occurrence in the United States the literature was searched 
for references to Spiroptera strongylina. Four such references were 
found, as below; in most cases Physocephalus sexalatus was probably 
also present but not recognized. 

1. Curtice (1892g), in a list of parasites infesting domestic animals 
and man in the United States, includes the following entry : "Spiroptera 
strongylina Rud. Host, Sus scrofa domestica. Location, stomach," 
followed by the remark, ' *Is often found with the food and attached to 
the walls." Specimens No. 2058 of the helminthological collection of 
the Bureau of Animal Industry were collected and identified by Cur- 
tice as Spiroptera stron{fylina. These specimens have been examined 
by the writer, who verified Dr. Curtice's identification. A few exam- 
ples of Physocephalus sexalatus were also present. 



THE ROUNDWORMS OP DOMESTIC SWINE. 33 

2. Stiles and Hassall (1894e) include Spiroptera strongylina in their 
preliminary catalogue of the parasites in the collection of the United 
States Bureau of Animal Industry. They report the parasite as com- 
mon. The specimens referred to by them (No. 2067 of the bureau 
collection) have been reexamined by the writer, and many specimens 
of Ph/ysocephalus sexalatus were found with the specimens of Arduenna 
stronffylina. Stiles and Hassall's specimens were collected at Ben- 
ning, D. C. 

3. Francis (1894a) reported Spiroptera sfrongylina in a list of para- 
sites collected by him in Brazos County, Tex. It is reported as com- 
mon. The specific name is followed by an interrogation point in 
parenthesis to indicate the author's doubt as to the correctness of the 
identification. Considering the inaccuracy of the descriptions of 
Arduenna strcmgylina, then available, it is not to be wondered that 
Francis, noticing the discrepancies between the descriptions and the 
anatomical features seen in his specimens, should question the identi- 
fication. On the other hand, it is quite possible that the specimens 
collected by Francis were Pkysocephalus sexalaius, or included this 

4. Kaupp (1910) reported the occurrence of Spiroptera strongylina 
in hogs raised in the Missouri Valley. His article is illustrated with 
original drawings, one of which shows the caudal end of the female 
with the vulva apparently on the right side, a little anterior of the 
anus. 

For the sake of additional data, letters were sent to the inspectors 
in charge at some of the principal slaughterhouses of the United 
States, requesting information in regard to the occurrence of Spirop- 
tera stronffylina in hogs. Replies were received from South Omaha, 
(Chicago, St. Louis, and Kansas City. The inspector in charge at 
South Omaha reported that fully 80 per cent of the hogs examined 
were infested. It was reported from St. Louis that **the worms 
occur in considerable numbers in the mucous coating of the stomach." 
The parasite is reported as very frequent in hogs slaughtered at 
Kansas City; out of 1,450 hogs examined, 1,052 were infested. In 
some stomachs as many as 140 worms were collected. From CJhicago 
it was reported that 1,000 hogs had recently been examined, and 690 
were found infested. The worms were found on the surface of the 
mucous membrane or attached by the head. Several hundred 
specimens obtained by scraping the mucosa from the stomachs of a 
number of infested hogs were received from this city. These worms 
were found to be Arduenna strongylina and PhysocepTialus sexalatus. 

Reports from slaughterhouses regarding the occurrence of parasites 
are of but little value in determining the localities infested by a given 
parasite, as the animals slaughtered are received from widely scat- 
tered sections of the country. Enough data have been gathered, 



34 THE KOUNDWOBMS OF DOMESTIC SWiKE. 

however, to warrant the assertion that the parasites occur throughout 
the middle and southwestern (and probably eastern) United States. 
Specimens have been collected by Hall in 1908 from a hog kept at 
Bethesda, Md., in all probability of eastern origin. They have also 
been collected by KQbome at Washington, D. C, and by Stiles and 
Hassall at Benning, D. C. ; in the latter case, however, it is possible 
that the host animal had been shipped to the local slaughterhouse 
from a Western or Central State. 

RELATIVE FREQUENCY OF THE TWO SPECIES. 

That Physocephalus sexaiatxis occurs less abundantly than Arduenna 
siroTiffylina in American swine is indicated by the following data: 

All the worms contained in a bottle of specimens forwarded from 
Chicago were sorted out by species and sex. The bottle contained 
744 specimens. Of these^ 599, or approximately 80 per cent, were 
ArdiLenna strongylina, and the remaining 145, or 20 per cent, were 
Physocephalus sexalatus. Of the 599 specimens of Arduenna strongy^ 
Una, 399, or 56 per cent, were females, and 260, or 44 per cent, were 
males. A smaller percentage of males was found among the speci- 
mens of PhysocepTudus sexalatus. Of the 145 specimens found, 69 
per cent were females and 31 per cent were males. 

LESIONS ASSOCIATED WITH AKDUENNA STBONOYUNA, ABDT7EN- 
NA DENTATA, AND PHYSOCEPHALUS SEXAULTU8. 

From an economic standpoint these three species are probably of 
considerable importance. Prior to 1899 it was not considered that 
Arduenna stronffylina was especially injurious to swine. Neumann 
(1892a), in mentioning that Spiroptera strongylina caused small sub- 
mucous tumors of the stomach and that no morbid disturbances^^ere 
attributed to it, summed up the general opinion of the time regarding 
the economic importance of the parasite. More recent reports, 
however, indicate that these parasites should be regarded as the 
possible etiology of serious gastric disorders. 

Von Rdtz (1899d) found Spiroptera strongylina very common 
among swine in Hungary, and attributed to this parasite several 
epizootics of a rather serious nature, in one of which, out of a herd of 
230 sows, 21 were seriously affected and 6 died. Some of the symp- 
toms were described as follows: 

The diseased sows suffered from loss of appetite , eating very little and in the worst 
cases finally refusing all food; on the other hand, they drank water excessively and 
were very restless, continually pawing the ground. 

Describing the post-mortem lesions seen in the stomach, Von R&tz 
says: 

At the pyloric end the mucous membrane was covered with a thick, lamellous, 
firmly adhering pseudomembrane, which upon being removed revealed a superficial 
loss of tissue of the mucous membrane. Under the mucous membrane lay numerous 



THE ROUNDWORMS OF DOMESTIC SWINE. 35 

Spiropiera strongylina fastened partly in the stomach wall, partly in the paeudo- 
membrane. In addition to theee lesions, dark red spots the size of a penny were to be 
seen, corresponding to which were numerous openings the size of a needle prick, 
through which projected the bodies of the nematodes. 

While no data are at hand regarding the effect of Arduenna dentaia 
on its host, iii view of its close similarity with Arduenna strongylina 
and the fact that both species are parasitic in the stomach, it may be 
assumed that the former species is as injurious as the latter. 

RaiUiet and Henry (1911b) report that the stomach of a sow from 
Madagascar from which specimens of PJiysocepJialus were collected, 
presented a very intense gastritis with a quantity of small elevations 
on the mucosa. 

The information and material supplied by the inspectors of this 
bureau have shown that lesions of a nature similar to those described 
by Von R4tz are frequently associated with the presence of Arduenna 
strongylina in this country. 

The inspector in charge at South Omaha reported that ''Ten per 
cent of the affected stomachs show a highly inflamed zone surround- 
ing the infested area, and in a few instances considerable ulceration 
exists." The inspector in charge at St. Louis was of the opinion 
that ''they produce no apparent lesions." The inspector in charge 
at Chicago forwarded, in addition to the loose specimens already 
mentioned, several pieces of hogs' stomachs showing the worms in 
situ. The heaviest infestations were found in portions from the 
pyloric end of the stomach, which in one instance presented the 
following appearances: A piece of stomach from the pyloric end 
about 21 cm. wide by 20 cm. long contained a cluster of worms buried 
in a glairy mucous mass of yellowish color firmly attached to the normal 
mucous membrane, and forming, in the opinion of pathologists in the 
Pathological Division of this bureau, to whom the tissues were referred, 
a pseudomembrane of necrotic tissue. Several such worm clusters 
were observ^ed on the portion examined, the worms in nearly every 
case being buried in a mass of mucus, and appearing as bright red 
lines in the yellowish mass. (See PI. I.) In places the necrotic 
tissue had apparently sloughed off, leaving deep, red, depressed areas 
of irregular shape. These areas varied in size from a few millimeters 
to 2 or 3 centimeters in diameter. The same lesions could be observed 
under the necrotic tissue when this had been removed with forceps. 
The condition was described by one of the pathologists as "undoubt 
edly ulcerous." 

It was suggested by the pathologists who examined the material 
that the pseudomembranes might have been caused by Bacillus 
necrophorus gaining an entrance to the submucosa as the result of the 
piercing of the mucous membrane by the parasitic worms; examina- 
tions of scrapings from the stomach lesions revealed a few specimens 
of the bacillus. As explained by Moliler and Morse (1904), this 



86 THB ROUNDWORMS OF DOMESTIC SWIKE. 

bacillus is normally found in the stomachs of hogs and other animals, 
and while under ordinary circumstances it has no pathological effect, 
if enabled through some lesion to the mucous membrane to gain 
access to impaired tissue, its proliferation results in the sloughing of 
the mucous membrane and the formation of ulcers. 

Mohler and Morse (1904), describing necrobaciQosis of the digest- 
ive tract, state: "The necropsy in such cases revealed hemorrhages 
and erosions in the stomach, but no areas of coagulation, ' ' an accurate 
description of the conditions found by the present writer. The char- 
acteristic odor described for lesions of Bacillus necrophorus was only 
faintly present, being modified perhaps by the boric acid with which 
the specimen was sprinkled and which may account for the paucity 
of the parasitic flora found. 

How deeply Arduenna strongylina is capable of penetrating into the 
submucosa was well shown in one of the specimens forwarded from 
Chicago. A piece of the cardiac portion of the stomach contained 
a worm 12 mm. long which had bored diagonally into the mucosa to a 
depth of 10 nmi., only the caudal end projecting above the surface. 
The hole made was similar to a pin prick, a simile used by Von R6tz 
(1899d) in describing the lesions observed by him. Indeed Von 
R&tz's description is practically identical with the conditions found 
by the present writer. 

The habit of boring into the mucosa characteristic of these para- 
sites would seem an ideal method of inoculating the submucosa of the 
host with Bdcillus necrophorus if any were present, and this, consid- 
ered in connection with the conditions observed in infested stomachs, 
indicates that the worms may be the indirect cause of grave ulcera^ 
tion. Considered apart from their possible rftle as infective agents, 
the mechanical injury to the stomach walls due to the penetration of 
the worms in numbers would seem to be a serious factor even if the 
worms were unassociated with bacilli. Moreover, the livid red color 
of the worms in situ in the stomachs examined would seem to indicate 
that they feed on blood, an additional reason for regarding them as 
dangerous parasites. The whole question, however, of the patho- 
genicity of the parasites, and as to their relationship to the lesions 
observed, remains open for further investigation. 

An examination of the stomach portions received showed specimens 
of Physocephalus sexalatus attached in the same manner as already 
noted for Arduenna strongylina; hence the former parasite may be 
considered only less dangerous than the latter, as it is less abundant. 

UFB HISTOBT. 

Nothing is known in r^ard to the development of the worms from 
the egg to the adult. The wide distribution, the frequency of the 
parasites, and the similarity of the eggshell to that of an ascarid, 



THE BOUNDWOBMS OP DOMESTIC SWINE. 37 

suggest the possibility that development occurs without an inter- 
mediate host. From the fact that the embryos are well developed in 
the uterus before oviposition^ it would seem that but Uttle time is 
required for incubation, and the thickness of the shell would indicate 
the necessity of the gastric juice of the host to dissolve the shell and 
liberate the embryo. 

FBBVBirnVE MBAST7BE8. 

In the absence of knowledge as to the life cycle of the parasiteS; no 
prophylaxis or treatment specially adapted to the case can be formu- 
lated. The following general prophylactic measures are suggested: 

1. Hogs suffering from loss of appetite or failing to fatten under 
proper food and hygiene should be examined for evidence of infection 
by killing one or two and looking in the stomach for worms; or, where 
practicable, the feces of the entire herd may be examined micro- 
scopically. 

2. Those swine found infested with stomach worms should be 
isolated from noninfested or presumably noninfested swine in clean 
pens, and the dimg removed daily and mixed with quicklime or 
disposed of by carting it to places to which hogs do not have access. 

3. The noninfested swine should not be allowed to remain in the 
same pens formerly occupied by the infested animals, but should have 
clean quarters. The old pens should be thoroughly disinfected with 
lime after removing the dung and burning over the ground where 
feasible. 

MEDICINAL TBEATKENT. 

Youatt (1847c), referring to Spiroptera strongylina, recommends 
turpentine and salt with the food for treating these worms. Coal-tar 
creosote, gasoline, and copper sulphate have been found more or less 
efficacious in treating stomach worms {Haemonehus contortas) in sheep, 
and similar treatment might be tried on pigs (see Bureau of Animal 
Industry Circular 102). Santonin and calomel, 3 grains each per 
hundred pounds of body weight, given after a fast of 12 to 16 hours, 
is another remedy which deserves trial. 

Whatever drug is used should first be given in small quantities and 
tried on a few of the most heavily infested swine, the size of the dose 
being increased as occasion demands. 



38 THE ROUNDWORMS OF DOMESTIC SWINE. 

KEY TO THE ROUNDWORMS PARASITIC IN DOMESTIC SWINE. 

The arrangement of the following key to the roundworms which 
have been reported by various authors as parasites of hogs is purely 
artificial and arbitrary and indicates nothing as to the systematic 
relationship of the different forms. A classified list of the roimd- 
worms of swine is given later on page 41. 

Section. 
Parasitic in alimentary tract 1 

Parasitic in respiratory tract — t 16 

Parasitic in other organs 17 

1. Diameter of body at middle over 3 mm 2 

Diameter of body at middle leas than 3 mm 3 

2. Anterior extremity .furnished with a protractile proboscis covered with spines. 

Male 6 to 10 cm. long, 3 to 5 mm. in diameter. Female 20 to 35 cm. long, 
4 to 9 mm. in diameter. Eggs, 87 to 100 ft long, subcylindrical, smooth, 
with 3 envelopes. In small intestine, usually attached to the mucous 

membrane GigantorhyncJiiuhirudtnaceus, 

Anterior extremity without protractile pro]K)8cis. Mouth with 3 prominent 
lipe. Male 15 to 17 cm. long, 3 to 3.2 mm. thick. Female 20 to 25 cm. 
long, 5 to 5.5 mm. thick. Eggs oval, 66 fi long, thick-shelled, surface cov- 
ered with mammillate projections. In small intestine, sometimes in biliary 
tract and pancreas Ascariit 8uum. 

3. Less than 5 mm. in length 4 

Over 5 mm. in length 5 

4. Vulva anterior of middle of body. Ovoviviimrous. Females 3 to 4 mm. 

long, 60 /i in diameter. Males 1.4 to 1.6 mm. long, 40 pi in diameter, with 
a short finger-like pn)ce8B on each side of the anal opening. Adults in 
small intestine, larvse encysted in skeletal muscles Tnchinella spiraUs, 

Vulva posterior of middle of Ix^dy. Females (parthenogenetic; parasitic 
males lacking) 3.75 mm. long, 80 fi in diameter. Eggs 45 fi long by 25 ft 

broad, with thin shells. In small intestine Slrongyloides suisA 

6. Head covered with spines; separated from the body by a deep constriction. 
Male 15 to 25 mm. long. Female 22 to 31 mm. long. Eggs 70 pt long by 39 
fi wide. In stomach Onathastoma hupidum. 

Head without spiny armature 6 

6. Posterior end of body of female with relatively large rosette-like excrescence 

containing the hypertrophied uterus. Male 12 mm. long. Female 15 mm. 

long. In stomach Simoncbna pcaradoza.* 

Posterior end of Ixidy of female without uterine rosette 7 

7. Anterior portion of body slender, like a whiplash, about twice as long as the 

thicker posterior portion. Male with single spicule. Male 33 to 40 mm. 
long. Female 34 to 50 mm. long. Eggs 52 to 56 /£ long, ellipsoidal, with 
an opening at each pole closed by a plug-like operculum, and brownish in 

color. In cecum Trichuri^ guts. 

Body continuous, not flagelliform anteriofly . Male with two spicules / 8 

1 While Strongyloides papiUostu (» Trichosoma papiUo«um Wedl.)a parasite of sheep has frequently been 
reported for the pig, this is probably the result of confusion with Strongyloida 9v.ii. The StrongyMdea of 
the pig is somewhat larger than the fom found in sheep. 

> Included by the present writer among the Filariidae on account of the inequality of the spicules. Its 
position in this family is not, however, defin tely established. Bee footnote on page 9, second paragnpb. 



THE EOUNDWORMS OF DOMESTIC SWINE. 39 

Section. 

8. Male witli two equal or subequal spicules; tail with membranous bursa sup- 

ported by paired rays and eggs with thin shells 9 

Male with two spicules of very unequal length; tail with lateral longitudinal 
bursal membranes supported by stalked pappill». Eggs with thin or thick 
shells 12 

9. Mouth enlaiged to forma buccal capsule 10 

Mouth small; buccal capsule not present. Male 5 mm. long. Female 8 to 8.5 

nmi. long. Spicules 130 ft long. Vulva about 2 mm. from the tip of the 
tail. Eggs, 45 fi long by 36 n wide. In stomach '^Strongylus " nibidus.^ 

10. Buccal capsule broader than long, mouth bordered by a crown of numerous, 

small, pointed processes. Male 8 to 12 mm. lon^*. Female 12 to 15 mm. 
long. Spicules slender, 1.13 mm. long. Vulva a short distance in front of 
anus, protuberant. Adults in large intestine, larvse encysted in the wall 
of the latge and small intestines, forming nodules. .CEesophagosUmvum dentcUum. 
Buccal capsule spherical or elongated, border of mouth smooth 32 

11. Buccal capsule spherical. Male 7 mm. long, 0.2 mm. thick. Female 8 mm. 

long, 0.3 mm. thick. Vulva prominent. In small intestine. 

Glohocephalus longemueronatus. 
Buccal capsule elongated, oval. Male 4.4 mm. long, 0.38 mm. thick. Female 
6.5 mm. long, 0,52 mm. thick. Spicules 590 /* long. Vulva sunken. In 
small intestine Croisisonia wrosuhulatum. 

12. Anterior end of body supplied with numerous cuticular tubercles or shields. . 13 
Anterior end of body without cuticular tubercles 14 

13. Male 30 to 50 mm. long by about 250 ft thick. Female 80 to 145 mm. long, 

300 to 350 fi thick. Left spicule 16 to 17 mm. long; right spicule 140 to 180 ft 
long. Vulva 4 to 5 mm. from tip of the tail. Eggs 55 to 60 /£ long by 32 to 
36 ft wide. In the mucosa of the esophagus and pharynx. 

Oongylonema scutatum? 
Male 14 to 50 mm. long, 175 to 195 ft thick. Female 37 to 40 mm. long (? or 
longer), 350 ft thick. Left spicule 4 to 5 mm. long, right spicule 84 to 110 
ft long. Vulva about 2 mm. from the tip of the tail. Eggs 52 to 56 /i long 
by 32 ft wide. In the mucosa of the esophagus and pharynx. 

Gongylonema pulchrum, 

14. Body furnished anteriorly with six longitudinal lateral wings, three on each 

side, the middle wing of each three wider than the other two. Ridges of 
pharynx forming a simple spiral, breaking up into separate wings. Male 
6 to 9 mm. long. Female 13 to 19 nun. long. Spicules 2. 1 to 2.25 mm . long, 
and 300 to 350 ft long, respectively. Vulva anterior of the middle of the 
body. Eggs 34 ft long by 15 ft wide, with rather thick shells. In stomach. 

Physocephalus sexalatu*. 
Anterior portion of body with a single longitudinal wing. Ridges of pharynx 
forming a continuous multiple spiral 15 

1 ** StrongjfUu*' nMdus does not belong in the genus Strongyhu. Its proper position Is in the family 
Trichostrongylinse. As yet, however, no genus has been established to which it may be assigned. 

s Reported by Eonil ( 1877a) and Plana ( 1896b). According to Neumann ( 1894d) , however, the measure- 
ments given by KorxU indicate that the species studied by him is QangyUmema pulchrum, Molin 1857. 
The measurenuBnts given by Plana ( 1896b) are, males 60 to 80 mm. long by 130 /t broad ; females 80 to 145 mm, 
king, 600^1 broad. Except that O. pulchrum is smaller than O. mmtatum, there is but little morphological 
diflerenoe between the two spedea. The species are considered identical by RaiUiet (18Q3a), although this 
view is not accepted by Neomann (1894d) and others. O. scuUUum is normally a parasite of ruminants. 



40 THE BOUKDWOBMS OF DOMESTIC SWIKB. 

Sectloii. 
15. Male 10 to 15 mm. long. Female 16 to 22 mm. long. Long spicule 2.24 to 
2.95 mm. in length, 5 to 6 times as long as tlie short spicule. Vulva some- 
what anterior of the middle of the body. Eggs M to 39 /i long by 20 /i wide, 

with rather thick shells. In stomach Arduenna Mtron^lina. 

Male 25 to 35 mm. long, 700 to 800 /i broad. Female 40 to 55 mm. long, 1.1 to 
1.2 mm. broad. Long spicule 3.75 to 4.23 mm. long. Short spicule 540 to 
650 ft long. Vulva three-eighths of the distance from the anterior end. 

Arduenna derUata, 
16.' Spicules about 4 mm. long, each terminated by a single hook. Vagina about 
2 mm. long. Male between 12 and 25 mm. in length. Female between 20 
and 50 mm. in lengtlib Vulva near anus. Eggs between 57 and 100 /i in 
length and 39 and 73;c in width. In trachea and bronchi. . Metastrongylus apri. 
Spicules 1.5 mm. long, each terminated by a double hook. Vagina about 
500 fi long. Male between 12 and 25 mm. in length. Female between 
20 and 50 mm. in length. Vulva near anus. Eggs between 57 and 100 /i 
in length and 39 and 72 /i in width. In trachea and bronchi. 

MeUutrongyluB hrevivaginahu, 

VJ? Encysted in skeletal muscles, microscopic in size. Cysts slightly elongated, 

ovoid, long axis parallel to the muscle fibers, about 400 ft long by 250 pt broad. 

Trickinella spiralis (larvse). 
Free in peritoneal cavity, in kidneys, in ureters, in the bladder, or encysted 
in fat of kidneys or loins 18 

18. Male under 40 mm. long 19 

Male over 12. cm. long 20 

19. Male 25 to 37 mm. long. Female 37 to 40 mm. long. Two spicules, equal or 

subequal, about 0.8 mm. long. Vulva less than 2 mm. from the tip of the 
tail. Eggs 100 fi long by 56 ;< wide, with thin'shells. In kidneys, ureters, 
and encysted in fat of kidneys and loins SUphanurus dentatus. 

20. Male 14 to 40 cm. long, 4 to 6 mm. in diameter. Female 20 cm. to 1 m. long, 

5 to 12 mm. in diameter. Spicule single, 5 to 6 mm. long. Vulva near the 
anterior end of the body. Eggs 64 to 68 ft long by 40 to 44 /t wide, thick- 
shelled, with pitted surface. In kidneys, ureters, peritoneal cavity, or 

bladder Dioctophyme viscerdUs^ 

Male 10 to 11 cm. Greatest diameter, 650 /i. Tail twisted in a loose spiral 
with a pointed end ; 8 pairs of papillse, 4 preanal and 4 postanal. Spicules 
unequal, the longer 215 ft long, 25 ft broad, with a membraneous extension 
70 ft long. Short spicule 140 ft long, 52 ft broad . Female 20 to 21 cm. long. 
Vulva 600 ft from the anterior extremity. Anus 300 ft from the posterior 
extremity. Eggs ovoid, 45 by 26 ft when fully developed. Viviparous. 
Parasitic in the peritoneal cavity Setaria bemardi. 

1 Railliet and Henry, 1911, describe a new species, jPUaHa&auc^,foundintlie"Iungs"ofahog8iaa^tered 
at Hu6, Indo-ChJna. The location of the parasite is not definitely known. The female alone was foond. 
It is reported as 22\ cm. long, with a maximum diameter of 635 /i. The body is transversely striated, the 
strlaB being 5 to 6 /i apart. Mouth unarmed , funnel-shaped , the cuticle thickened at the anterior end. Anus 
155 /t from the posterior extremity; vulva 1.1 mm. lh)m the mouth. 

* Oigantorhynehtu Mrudinaeeut, although normally located in the intestine, sometimes i)erfonktes the 
intestinal wall, in which case it may be found in the peritoneal cavity. (See No. 2 of this key, first parar 
graph.) 

Aicarit tuum may be found aberrant In various locations outside the digestive tract. Diagnostic char- 
acters for the identification of this species have already been given. (See No. 2 of this key, seoHid 
paragraph.) 

* Included by Von Linstow (1878a) among the parasites of the domestic hog, but its occurrence in this 
host is questionable. 



THE ROUNDWORMS OP DOMESTIC SWINE. 41 

CLASSIFIED LIST OF BOUNDWOBMS PABASITIC IN DOMESTIC 

SWINE. 

Specific descriptions are omitted from the following list as these 
have already been^ given in the key to the roundworms of swine. 
Arranged according to their respecive orders, famiUes, and genera, 
the roundworms reported as parasitic in domestic swine are as follows: 

Class Nemathelminthes: Cylindrical worms without a prebuccal ciliary apparatus 

provided with a variable nervous system, not forming a ventral 
chain. Generally dioecious. 
Order Nematoda. Nemathelminthes: Provided with a complete digestive tube. 
Family Angiostomidse. Nematoda: Having two heterogenetic generations, 
one of free-living males and females aad one of hermaphroditic 
or parthenQgenetic forms which are parasitic. 
Genus Strongyloides. Angiostomidse: Parasitic form with mouth 
opening directly into the relatively very long subcylindrical 
esophagus. Vulva posterior of the middle of the body. Uterus 
double. Two ovaries. Free-living form with mouth opening into 
a vestibule or pharynx, followed by an esophagus whose anterior 
portion is fusiform and posterior portion globular. 

Strongyloides suis. 
Family Gnathostomidse. Nematoda: Body furnished throughout its length, 
or only anteriorly, with chitinous blades or wings, serrated posteri- 
orly. Head subglobular, covered with simple spines. 
Genus Gnathostoma: W^ith the characteristics of the family. 

Gnathostoma hispidum. 

Family Trichinellidee. Nematoda: Esophagus consisting of a chain of single 

cells, the lumen of the esophagus passing through the center of 

each cell. Anterior portion of body containing the esophagus 

usually very slender; posterior portion containing the intestine 

and reproductive oigans more or leas swollen. One testicle, one 

ovary. 

Subfamily Trichinellinee. Trichinellidse : Male without spicule . Female 

ovo viviparous. Adults in intestine of host produce larvae which 

penetrate into the muscles, become encysted, and develop to 

maturity when the flesh of this animal is eaten by another animal. 

Genus Trichinella. Trichinellinse : Very small worms with capillary 

bodies. Progressively increasing in diameter posteriorly. Male 

with two conical posterior appendages forming a copulatory bursa. 

Vulva of the female in the anterior fifth part of the body. 

Trichinella spiralis. 

Subfamily Trichurin^. Trichinellidse: Male with spicule. Female 

'deposits eggs characterized by the presence of an opening at each 

pole closed by a pluglike operculum. Eggs do not hatch until 

swallowed by a suitable host. Development, so far as is known, 

direct, without an intermediate host. 

Genus Trichuris. Trichurinse: Anterior portion of body very long 

and slender. Posterior portion of body containing the intestine 

and reproductive organs relatively thick and much shorter than 

the anterior portion. Posterior portion of male rolled dorsally 

into a spiral. Spicule surrounded by a prepuce-like sheath. 

Posterior portion of body of female slightly curved. Vulva near 

the beginning of the posterior portion of body IHchtaris suis. 



42 THE BOITKDWOBMS OF D0ME6TI0 SWlKS. 

Family Filariid». Nematoda: Body long, filiform. Mouth surrounded with 
papilke, or provided with two lipe. Eaophagus slender, without 
posterior bulb. Males with two unequal spicules (sometimes with 
a single spicule). Females with two ovaries. Vulva usually- 
anterior of the middle of the body. Development often requires 
an intennediate host. 

Genus Filaria. FUariidee : Body long and slender, of nearly uniform 
diameter throughout; males considerably smaller than the females, 
with the tail hooked or curved in a spiral, sometimes furnished 
with lateral wings. Usually there are four preanal and a variable 
number of postanal papilhe. Spicules usually very different in 
shape and dimensions. Vulva inore or less near the mouth. 

Filaria bauchei. ^ 

Genus Setaria. Filariidse: Head armed with a projecting peribuccal 
circle, deeply notched laterally, somewhat lees indented dorso-ven- 
trally, giving the impression of two teeth when seen laterally and 
of four teeth when seen at an angle. Tail of both sexes provided 
with two special appendices Setaria bemardi. 

Genus Gongylonema. Filariidfie: Body filiform, slightly attenuated 
at either end. Anterior portion of body covered with nimieroufl 
tubercles or shields formed by differentiation of the cuticle. In 
the median lines immediately behind the mouth, two semilunar 
depressions, one dorsal, the other ventral. Tail of male curved 
ventrally, supplied with two asymmetrical membranous wings. 
Vulva a short distance anterior of the anus. .Gongylonema scutatum. ' 

Gongylonema ptdchrum. 
Subfamily ArduenniuBe. Filariidse:* Mouth with two lateral lips leading 
into a pharynx marked with cuticular ridges in the form of spirals 
or rings. Spicules imequal, the longer several times the length of 
the shorter. Four pairs of preanal papillse. Eggs containing 
embryos at the moment of oviposition. 

Genus Arduenna. Arduenninse: Mouth leading into a cylindrical 
pharynx marked by ridges, forming a continuous multiple spiral. 
Esophagus continuous, nearly one-third of the length of the body. 
Spicules very long and very unequal. Tail twisted in a single 
coil. BureA asynunetrical, supported by five pairs of papillae. 

Arduenna strongylina. 
Arduenna dentata. 

Genus Physocephalus. Arduenninse: Body furnished anteriorly 
with six lateral wings arranged in a group of three wings each, on 
either side . The middle wing of each group is the widest . Pharynx 
cylindrical, relatively broad and long, marked with a simple spiral 
ridge on the inside, breaking up into separate rings and resuming 
the spiral at the posterior end ^ . . PhyBocephalus 9exalatu8, 

Genus Simondsia.^ Filariidse: Female characterized by a t^^men- 
tary excrescence in the form of a rosette situated in the posterior 
part of the body and inclosing a prolongation of the intestine and 
a hypertrophied uterus Svirumdgia paradoxa. 

1 This species, described by Railliet and Henry (1911), is proyisionally included in the genus Filaria, 
seruu lato. As only one female was received, the material was insufficient for a more accurate generic 
diagnosis. 

* See footnote 2, p. 39. 
s See footnote, p. 9. 

* Railliet and Henry (1911b) include Simondsia in the subfamily Arduennlnie, although Plana (1897e) 
describes the lips as dorao-ventral rather than lateral. In the stnicture of the esopliagua, the number 
of preanal papulae, and the inequality of the spicules Simondsia oonf(»ins to the description of the sub* 
tEunily Arduenninas. 



THE BOUNDWORMS OF DOMESTIC SWINE. 43 

Family StiungylidsB. Nematoda: Head with eix more or less distinct circu- 
moral papillae. Males with a more or lees well-developed bursa, 
each lateral lob^ of which is usually supplied with six supporting 
rays. Spicules equal or subequal. Vulva may be anterior to the 
middle of the body, but is usually posterior. Oviparous. De- 
velopment, so far as known, direct without intermediate host. 
Subfamily Strongylinfie. Strongylidse: Buccal capsule well developed. 
Eggs in the process of segmentation at the moment of oviposi- 
tion. Embryo nearly always rhabditiform and development di- 
rect. Parasitic in the alimentary canal; exceptionally in the res- 
piratory system. ; 

Genus (Esophagostomum. Strongylinee: Head 75 /i or more in diam- 
eter; buccal capsule small. Cuticle surrounding the mouth usually 
inflated to form a ringlike mouth collar. Bursa of male with two 
lateral lobes united by a smaller median lobe. Spicules more than 
0.5 mm. long, slender, tubular, pointed ; gubemaculum present, but 
not conspicuous (EgopJtagostomum dentaium. 

Genus Globocephalus. Strongylinse: Buccal capsule cylindrical, 
larger in diameter than the thickness of the body, supported by 
two chitinous rings — one at the anterior end of the capsule, the 
other at the posterior end. The rings are joined by four chiti- 
nous longitudinal bands GlobocephaliLS longemturonatus. 

Genus Crassisoma. Strongylinae: Buccal capsule oval, smaller in 
diameter than the thickness* of the body, supported by eight longi- 
tudinal thickenings of the cuticle, and a chitinous ring on the 

inside of the capsule CranisoTna urotubulatum. 

Subfamily Trichostrongylinse. Strongylidee: Buccal capsule absent or 
slightly developed. Eggs generally segmenting at the time of 
oviposition. Embryo rhabditiform and development direct. 
Parasitic in the alimentary canal. 

Genus. Undetermined * Strongyhis rubidus. 

Subfamily Metastrongylinse. Strongylidee: Buccal capsule absent or 
slightly developed. Eggs in various stages when oviposited. 
Embryo rhabditiform. Evolution unknown, perhaps requiring an 
intermediate host. Parasites of the respiratory or circulatory 
system. , 

Genus Metastrongylus. Metastrongylinae: Mouth with six lips. 

Postero-lateral ray much reduced or absent. Dorsal ray and 

extemo-dorsal rays slender, the others thick. Two very long 

spicules. Vulva close to the anus. Eggs with well-developed 

embryos. Parasitic in the bronchi and trachea. 

Metastrongylus apri. 

Metastrongylus brevivaginatvs. 
Subfamily not determined. 

Genus Stephanurus. Strongylidse: Anterior extremity truncated; 

mouth suborbicular, limited by a chitinous ring furnished with 

teeth. Caudal bursa of male with many lobes. 

Stephanurus dentatus. 

1 See footnote 1 on p. 39. 



44 THE BOUNDWORMS OF DOMESTIO SWINE. 

Family not determined.^ 

GenuB Dioctophyme. Nematoda: Body cylindrical, mouth without 
lip0, BuiTounded by papillae. Male fumished with a filiform 
spicule. Femlile with a single ovary. Vulva in the anterior -pgurt 
of the body Dietophyme vitceralis. 

Family Ascaridie. Nematoda: One lip median, dorsal; two submediaiiy 
ventral. Relatively thick forms. Males provided with two 
spicules. Females with double ovary. 
Genus Ascaris. Ascaride: Furnished with three strong lips, the 
lateral sides of which are generally toothed. Males with two equal 
or subequal spicules and numerous papilke anterior and posterior 
of the anus. Vulva located anterior of the middle of the body. 
Eggs globular or ellipsoidal, usually surrounded by an albu- 
minous envelope. In process of segmentation at the time of ovi- 

position Agcctris tuum. 

Order Acanthocephala. Nemathelminthes without mouth or digestive tube. 

Furnished with a protractile proboscis armed with hooks. 

Family Gigantorhynchidse. Acanthocephala: Body laige and annulated; 
tseniaform. Hooks of the proboscis with two roots and covered 
with a transparent layer of chitin. Lemnisci lengthened into the 
form of rounded bags and having a central canal. 
Genus Gigantorhynchus; with the characteristics of the family. 

GigarUorhynchus hinidinacetis. 

- 

1 Dioetopkjfvu vi9eerali§ although oommonly Included in the tarnHj Strongylids does not oonfonn to all 
the characteristics of this ftunily. It more closely resembles the FUariidie as pointed out by RaUlet and 
Hsory (1900a). Probably It should be placed in a tunily by Itself bat the question is open to further study. 



DK Blainyille, Marie Henri Ducrotat. 

1828a.— Vera <I>ict. d. ec. nat., Par. & Straeb., v. 57, pp. 365-625 (p. 546), pb. 
27-28. 

Brbmsbr, Joannes Godofredus. 

1811a. — Nachiicht von einer betrfichtlichen Sammlung thierischer Eigeweide- 
wfknner [etc.], 31 pp., 1 1. 4*. Vindobonae. 

1824c. — Icones helminthum systema Rudolphi entozoologicum illustrantefl. 12 
pp., 18 pis., fol. VienniB. 

Ciueea, Joan. 

1911. — ^Ueber Spiroptera atrongylina Rud. <Centralbl. f . Bakt. Paraatenk. [etc. J, 
1 Abt. Orig., V. 61 (1-2), Nov., pp. 128-133. 

1912. — Ueber Spiroptera aexaUUa Molin. au8 dem Magen des HaiuMchweines. 
Zool. Jahrb. Abt. f. Syst. Geog. iind Biol, der Tiere., v. 33 (3), pp. 285-294. 

CoBBOLD, Thomas Spencer. 

1864b. — Entozoa; an introduction to the study of helminthology, with refexence, 
more particularly, to the internal parasites of man. 3Lxvi4-480 pp., 82 figs., 
21 pis., 8®. London. 

1879b. — ^Parasites; a treatise on the entozoa of man and animals, including some 
account of the ectozoa. xi-f 508 pp., 85 figs. 8^. London. 

Curtice, Cooper. 

189^. — ^Parasites. Being a list of those infesting the domestic animals and man 
in the United States. <J. Comp. M. and Vet. Arch,, N. Y., v. 13 (4), Apr., 
pp. 223-236. 

DiBsiNQ, Karl Morttz. 

1851a. — Systema helminthum. v. 2, vi+588 pp., 2 1. 8*. Vindobonee. 

1861a. — Revision der Nematoden. <Sitzung8b. d. k. Akad. d. Wiasensch., 
Wien, Math.-naturw. CI. (1860), v. 42 (28), 6 Dec, pp. 595-736, 1 pi., figs. 
1-11. 

YON Drasche, Richard. 

1884a. — Revision der in der Nematoden-Sammlung des k. k. zoolo^schen Hof- 
cabinetes befindlichen Original-Ezamplare Diesing's und Mohn's. <Ver- 
handl. d. k. k. zool.-bot. Gesellsch. in Wien (1883), v. 33, pp. 193-218, pis. 
11-14. 

Dttjardin, Ytux. 

1845a. — Histoire naturelle des helminthes ou vers intestinaux. xvi+654+15 
pp., 12 pis. 8*. Paris. 

Foster, Winthrop D. 

1911. — Note on Spiroptera stronmlina and Phygocephalus aeocalatvs. In The Hel. 
minthological Society of Washington. <Science N. S., v. 33 (850), April 14, 
pp. 590-592. 

FRANas, Mark. 

1894a. — ^Veterinary science. <Bull. 30, Texas Agric. Exper. Station, Temple, 
Mar., pp. 439-458, pis. 1-3. 

GuRLT, Ernst Friedrich. 

1831a. — ^Lehrbuch der pathologischen Anatomie der Haus-Saugethiere. Nebst 
einen Anhange, welcher die Beschreibung der bei den Haus-S&ugeihieren 
vorkomenden Eingeweidewtkrmer enthalt. v. 1, xx+399 pp. 8*. Berlin. 

1847a. — ^Ueber einige Eingeweidewtbrmer. <Mag. f. d. ges. Thierh., Berl., v. 13 
(1), pp. 74-77, pi. 1, figs. 3-9. 

Hassall, Albert, & Stiles, Charles Wardell. 

1892a. — Strongylus rvbiduB, a new species of nematode parasitic in pigs. ^J. 
Comp. M. and Vet. Arch., N. Y., v. 13 (4), Apr., pp. 207-209, figs. 1-3. 

45 



46 THE ROUNDWORMS OF DOMESTIC 8WINB. 

Kaupp, Benjamin Franklin. 

1910. — Spiroptera strongylina. MisBouri Valley Vet. Bull., Topeka, Kami., v. 4 
(11), Feb., pp. 2»-31, figs. l-A. 

m 

KORZIL, R. 

1877a. — Spirovtera 9cutata in Epithel der Zuog^ und desSchlundes beim Schweine. 
<0e8teiT. VrtlJBchr. f. wiflflensch. Veterinftrk., Wien, v. 48 (2), pp. 220-222, 1 pi., 
figs. 1-5. 

Lbiper, Robert T. 

1908. — ^An account of some Helminthea contained in Dr. Wenyon's collection from 
the Sudan. <3 Rep. Wellcome Research Lab., Lond., pp. 187-199, figs. 44-50, 
pis. 21-22. 

1911. — Some new parasitic nematodes from Tropical Africa. <Proc. Zool. Soc. 
Lond. (2), June, pp. 549-555, figs. 140-144. 

VON LiNBTow, Otto Friedrich Bbrnhard. 

1878a. — Compendium der Helminthologie. [etc.] xxii-}-382 pp. 8*. Hannover. 

1879b. — Helminthologische Untersuchungen <Jaresh. d. Ver. f. vaterl. Naturk. 
in WQrttemb., Stuttg., v. 35, pp. 313-542, pi. 5, figs. 1-24. 

1886c. — [Nematodes, trematodes and Acanthocephala collected by Fedtschenko 
in Turkestan.] (Fedtschenko. Travels in Turkestan. Pt. 18, v. 2» Zoogeo- 
graphical Survey (5).) [Russian text.] <Izvie8t. Imp. Obsh. Liub. Estestr 
vozn. [etc.], Moskva, v. 34 (3), 40 pp., figs. 1-55. 

1904f. — Nematoda in the collection of the Colombo Museum <Spolia Zeylanica, 
V. 1 (4), Feb., pp. 1-14, pis. 1-2, figs. 1-27. 

MoHLER, John R.; & Morse, Gborob Byron. 

1904. — Bacillv^ necrovhorm and its economic importance. 21st An. Rep., Bureau 
Animal Indust., U. S. Dept. Agric, Wash., pp. 76-116. 

MouN, Raffaele. 

1860b. — Una monografia del genere Spiroptera <Sitzimgsb. d. k. Akad. d. Wi»- 
sensch., Wien, math.-naturw. CI., v. 38 (28), pp. 911-1005. 

Mueller, Otto Friedrich. 

1787a. — Verzeichniss der bisher entdeckten EingeweidewtUmer, der Thiore. in 
welchen sie gefunden worden, und besten SchJiften, die derselben erwahnen 
<Naturfor8cher, Halle, v. 22, pp. 33-86. 

Neumann, Louib-Georqes. 

1892a. — ^Trait6 des maladies parasitaires non microbiennes des animaux domes- 
tiques. 2 6d. xvi+767 pp., 364 figs. 8». Paris. 

1894d. — Sur le genre GongyUmenuif Molin <M^m. Soc. zool. de France, Par., 
V. 7 (4) pp. 463-473, figs. 1-4. 

Oerlet, Ladislaud. 

1885a. — A czdpdknak es Rdj&knak belf^rgei <Term68zet. fiizetek, Budapest, 
V. 9 (2), apr.-junius, pp. 97-126, pis. 9-10, figs. 1-23. 

Piana, Giovanni Pietro. 

1896b. — Gorujylonema scutatum (M tiller) nell* esofago delle pecore "<Clin. Vet., 
Milano, v. 19 (13), 28 mar., p. 147. 

1897e. — Ricerche sulla morfol(^a della Simondsia paradoxa Cobbold e di alcuni 
altri nematodi parassiti dello stomaco degli animali della specie Su8 scrofa 
L. <Atti. Soc. ital di sc. nat. [etc.], Milano, v. 37 (1), giugno, pp. 17-37, figs. 1-7. 

Railliet, Alcide. 

1893a. — ^Trait6 de zoologie mMicale et agricole. 2 ^d. [fasc. 1] 736 pp., 494 
figs. 8®. Paris. 

Railliet, Alcide; & Henrt, A. 

1909a. — Sur la classification des Strongylida: I — ^Metastrongylinse <Compt. 
rend. Soc. de biol., Par., v. 66 (2), 22 Jan., pp. 85-88. 

1911. — Remarques au sujet des deux notes de Mm. Bauche et Bernard. <Bull. 
de la Soc. de Path, exotique v. 4 (7), 12 juillet, pp. 487-488. 

1911b. — ^Helminthes du pore recueillis par M. Bauche en Annam <lbidein« 
V. 4 (10) 13 dec, pp. 693-699. 



THE ROUNDWORMS OF DOMESTIC SWINE. 47 

VON RAtz, Stbphan. 

1899d. — Parasiten im Magen des Schweiues <Zt8clir. f. Thienned.,'Jena, v. 3 
(4-^), pp. 322-329. 

BuDOLFHi, Carl Asmund. 

1819a. — Entozoonim synopsis cui accedunt mantissa duplex et indices locuple- 
tissimi. x +811 pp., 3 pis. 8^ Berolini. 

Schneider, Anton. 

1866a. — ^Monographie der Nematoden. viii+357 pp., 122 figs., 28 pis., 343 figs. 
4». Berlin. 

Skurat, L. G. 

1912. — Bur la presence, en Alg^rie, du Spiroptera sexalata Molin, chez le Droma- 
daire et chez I'Ane <Compt. rend. Soc. de Biol., Par., v. 72 (5) 9 f6v., pp. 
174-176. 

Stiles, Charles Wardell; & Hassall, Albert. 

1894e. — A preliminarv catalogue of the parasites contained in .the collections of 
the United States Bureau of Animal Industry, U. S. Army Med. Museum, Bio- 
logical Dept. of the University of Pennsylvania (Coll. Leidy) and Coll. Stiles 
and Coll. Hassall <Vet. Mag., Phil., v. 1 (4), Apr., pp. 246-253; (5), May, pp. 
331-354. 

1905b. — ^The determination of generic types, and a list of round-worm genera, 
with their orinnal aud type species <Bull. 79, Bureau Animal Indust., U. S. 
Dept. Agric, Wash. pp. 1-150. 

Stossich, Michble. 

1897b. — Filarie e Spiroptere. Lavoro monografico. pp. 13-162. (150 pp.) 8*. 
Trieste. 

YOUATT, WnxiAM. 

1847c. — ^The pig: A treatise on the breeds, management, feeding, and medical 
treatment of swine; [etc.] viii+164 pp. 8^ London. 

ZuERN, Friedrich Anton. 

1882a. — Die Schmarotzer auf und in dem Rdrper unserer Hauss&ugethiere, sowie 
die durch erstere veranlassten Krankheiten, deren Behandlung und VerhUtung. 
1 Theil: Tierische Parasiten. 2 Aufl., xvi-f 316 pp., 4 pis. 8». Weimar. 



additional copies of this publlcatloil 
-L^. may be prooared fh>in the Bupebinteni>> 
XNT or DocuXENTB, GoYemment Printing 
Office, ^aahlngton, D. C, at 10 oento per copy 







IfaOBd Octobn U, mi. 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 159. 

A. a MELVm, Our or Buuau. 



FEEDING BEEF CATTLE IN ALABAMA. 

I. Winter Fattening <m Cottonaeed Meal, Cottonwed 

Hnlls, Corn Silage, ud Johnson-Orua Bay. 
n. 'WlIlteTiI^[ Steers followed by Summer Fattening 

on Future. 
m. The Value of Shelter for fattening Cattle in 

Alabama. .,'•■■ 

IV. Early Compared with Xate Fattening «f fitoen 
on Pasture. 



DAN T. GRAY, 

IVoftssor of Animal Industry, Alabama Fblylechnic InstituU, 

AND 

W. F. WARD, 

Junior Animal Husbandman, Animal Husbandry Z^itdiion. 



BUREAU OF ANIMAL INDUSTRY. 



Chief: A. D. Melvin. 

Assistant Chief: A. M. Farrinoton. 

Chief Clerk: Charles C. Carroll. 

Aniinal Eushandry Division: Gborob M. Romkel, chief. 

Biochemic Ditnsion: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsat, chief. 

Meat Inspection Division: Rice P. Steddom, chief. 

Pathological Division: Johk R. Mohlbr, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Divinon: B. H. Ransom, chief. 

Rcperiment Station: E. C. Sghroeoer, superintendent. 

Editor: James M. Pickens. 



.LETTER OF TRANSMITTAL. 



United States Department op Agriculture, 

Bureau of Animal Industry, 
Washington, D. G., July 10, 1912. 

Sm: I have the honor to transmit herewith, and to recommend 
for publication in the buUetin series of this bureau, a manuscript 
entitled "Feeding Beef Cattle in Alabama," by Messrs. Dan T. Gray, 
professor of animal industry in the Alabama Polytechnic Institute, 
and W. F. Ward, junior animal husbandman in the Animal Hus- 
bandry Division of this bureau. 

This bulletin presents further results of the investigations in beef 
production which have been carried on during the past seven years 
by the bureau in cooperation with the Alabama Experiment Station, 
former pubUcations being Bulletins 103, 131, and 147. The work 
is being continued and other problems relative to the feeding of beef 
cattle in the South are being studied. 

Respectfully, A. D. Melvin, 

Chief of Bureau. 

Hon. James Wilson, 

Secretary of Agriculture. 



CONTENTS. 



I. WINTER PATTBNINO OP STEERS ON COTTONSEED HEAL, COTTONSEED HULLS, CORN 

SILAGE, AND JOHNSON-GRASS HAY. 

Page. 

Intzoduction 9 

Object of the experiment 9 

The cattle 10 

Method of conducting the work 10 

Price and character of feeds 11 

Preliminary feeding 11 

Daily rations 12 

DaUy and total gains 14 

Quantity and cost of feed required to make 100 pounds gain 15 

Advantages of using purchased feeds 17 

Value of barnyard manure 17 

Financial statement 18 

Slaughter data 20 

Summary 20 

n. WINTERING STEERS FOLLOWED BY SUMMER FATTENING ON PASTURE. 

Introduction .• 22 

Object of the work i 22 

The cattle 23 

The pastures 23 

The winter range 23 

Plan of the feeding 24 

Character and price of the feeds 25 

The winter feeding 26 

Daily rations 26 

Weights and gains during winter months 27 

Quantity and cost of feed required to make 100 pounds gain during the 

winter 28 

The spring cost of the steers 29 

Fattening the cattle on pasture 30 

Daily rations 31 

Weights and gains on pasture 32 

Quantity and cost of feed required to make 100 pounds gain 33 

Financial statement of the summer feeding 34 

Slaughter records 37 

Summary 37 

5 



6 ' CONTENTS. 

m. THB YALUB OF SHELTER FOR FATTENING CATTLE IN ALABAMA. 

Page. 

IntToduction 40 

Plan of the experiment 41 

The cattle : 41 

Preliminary management and feeding 42 

Lots and shelter 42 

Character and price of feeds 43 

Daily rations 43 

Weights and gains 44 

Quantity and co.^t of feed required to make 100 pounds gain 44 

Profits on cottonseed meal and hulLj as a result of feeding them to the cattle. . . 45 

Financial statement 45 

Sunmmry 46 

IV. EARLY COMPARED WITH LATE FATTENING OF RTEERS ON PASTURE. 

Introduction 48 

Plan of the work 48 

The cattle and the pasture 49 

Quality and price of feeds 50 

Daily rations 50 

Totfid and daily gains 52 

Quantity and cost of feed required to make 100 pounds gain 53 

Financial statement 54 

Summary 55 



INTRODUCTORY NOTE. 



Among the facts of importance demonstrated in this bulletin are 
(1) the outstanding value of a ration of cottonseed meal and cotton- 
seed hulls as a standard beef-making ration in Alabama when fed 
in winter; (2) the small necessity for shelter for beef cattle in Alabama; 
and (3) the great importance of the use of pasture for cattle when 
fed a summer ration of cottonseed cake. The authors have opened 
up an additional field for the use of pasture by their investigations 
of the relative value of short and long period feeding on smnmer 
pasture. 

In this connection I take the opportunity again to point out the 
importance of these investigations not only to Alabama and other 
parts of the South but to the entire country as well. This work is 
laying the foundation for rational and profitable beef production 
under southern conditions and will grow in influence with the advance 
of the boll weevil and the eradication of the Texas-fever cattle tick. 
In this respect it will be worth far more to the South than the entire 
amount of the appropriation which makes it possible. 

The importance of the work to the country at large lies in the 
fact that every square mile freed from ticks opens up just that much 
more territory to beef production and tends to offset the restriction 
of the western range by settlement, which in turn has already greatly 
restricted the western cattle output. With the extermination of 
the ticks wiU come a demand for information on how to feed beef 
cattle profitably, and that demand, I believe, can be met very largely 
by the results of these investigations. Prof. Gray and his assistants 
are demonstrating that cattle can be fed in Alabama at a cost far 
below that common in the com belt, and this often with inferior, 
underbred, or even scrub cattle. If such results can be obtained 
with cattle which are seldom more than half or three-quarters pure; 
what may we not in reason expect with the improvement in breed- 
ing which will surely follow the eradication of the tick ? 

The United States faces a beef-cattle shortage. The cattle ranges 
of the West are every year being diminished in area by settlement. 
In the South, east of the Mississippi River, are enormous areas of 
practically idle land, suitable for pasture, where beef cattle can and 
should be raised and fattened. Is it too much to predict that in 
this* section of our country will come the next great expansion of 
the beef-producing business in America? 

George M. Rommel, 
Chief of Animal Husbandry Diinsion. 

7 



FEEDING BEEF CAHLE IN ALABAMA. 



L WINTER FATTENING OF STEERS ON COTTONSEED 
MEAL, COTTONSEED HULLS, CORN SILAGE, AND 
JOHNSON-GRASS HAT. 



INTRODUCTION. 

Cottonseed meal and cottonseed hulls, the two feeds which in 
the past have been used almost exclusively during the winter months 
for fattening'cattle in the South, have advanced in price very mate- 
rially during the last three or four years. This advancement in 
price has forced the southern farmers to seek feeds with which to 
supplement the cottonseed meal and hulls. In the experiment here 
reported, silage and Johnson-grass hay were used as supplementary 
feeds to the hulls. Cottonseed meal was the only concentrated feed 
employed. 

Since the inauguration of the cooperative beef work by the Bureau 
of Animal Industry and the Alabama Experiment Station some 
resiilts have been published relative to winter fattening of steers,^ 
but silage and Johnson-grass hay were not introduced into any of 
the former rations. It should be understood that this bulletin is 
only a report of the progress of the cooperative beef work, as the 
experiments are being continued. 

OBJECT OP THE EXPERIMENT. 

This experiment was planned with the following objects in view: 

1. To determine the profit, if any, in fattening a good grade of 
cattle in the winter time on high-priced feeds. 

2. To compare a ration of cottonseed meal and hulls alone with a 
second ration of cottonseed meal, hulls, and silage, and with a third 
ration of cottonseed meal, hulls, and Johnson-grass hay. 

The steers were divided into three lots of 20 in each, and were 
given the following feeds : 

Lot 1. — Cottonseed meal, cottonseed hulls, com silage. 

Lot 2, — Cottonseed meal, cottonseed hulls, Johnson-grass hay. 

Lot 3. — Cottonseed meal, cottonseed hulls. 

1 See Bureau of Animal Industry Bulletin 103. 
54012*— BuU. 159—12 2 * 9 



10 FEEDING BEEF CATTLE IN AI^BAMA, 

THE CATTLE. 

The cattle were better than the average cattle of the South. 
They were all purchased in Sumter and neighboring counties during 
the fall of 1909, and were the best of a herd of about 300 head of 
improved cattle. None of them was purebred, but all had been 
graded up by the use of Hereford, Aberdeen-Angus, and Shorthorn 
sires. They varied from 2 to 3 years in age. The average weight 
of each animal at the beginning of the test was approximately 830 
pounds, so they were larger than the average southern cattle. The 
increased size was due to the improved beef blood. 

As these cattle were better than the average cattle of the State, 
they cost more in the fall than is usually paid for Alabama cattle. 
They were valued at S{ cents a pound when the test began, Decem- 
ber 1, 1909. 

METHOD OF CONDUCTING THE WORK. 

The cattle were fed under average farm conditions. Mr. F. I. 
Derby, a farmer and stockman of Sumter County, Ala., agreed to 
cooperate with the Bureau of Animal Industry and the Alabama 
Experiment Station in this work, and the feeding was all done upon 
his farm. Mr. Derby furnished the cattle and the feed, and the work 
was planned and the feeding carried on under the supervision of the 
authors of this bulletin. Mr. J. W. Ridgway was stationed upon the 
farm and had personal supervision of the experiment. 

No artificial shelter was provided for the cattle and as no trees were 
in the feed lots, they did not even have the protection which trees 
afford. They were fed in the open fields, as no shelter is needed in 
Alabama for mature fattening cattle. As Mr. Derby's main object 
in feeding cattle is to enrich his farm, the cattle were fed on areas 
which were to be subsequently planted in either cotton or com. The 
cattle were fed upon fields consisting of about 10 acres of land to each 
lot of 20 cattle. While no accx)unt was kept of the amount of manure 
made, still it is known from subsequent work that the 60 head of 
cattle made at least 1 ton of manure each day, or 84 tons for the 
whole feeding period of 84 days. The manure, of course, added very 
much to the fertility of the land upon which it was dropped. 

Many of the clay soils of the State would be ruined by tramping 
if the cattle were permitted to stay on them during the wet winter 
weather. The soil of Mr. Derby's farm is a light, sandy one, so the 
tramping of the cattle did not injure it materially. However, since 
this work was done, Mr. Derby has come to the conclusion that the 
winter tramping injures even a sandy soil, so hereafter he intends to 
feed in sheds and bams and haul the manure to the fields. 



WINTER FATTENING OP STEERS. ' 11 

The steers were fed twice each day in open troughs located in the 
fields. The troughs were made so that they could be moved from 
place to place, thus insuring an even distribution of manure and 
avoiding too much packing of the soil in one place. The steers were 
fed in such amounts that the feed was all eaten within a few hours 
after it was put before them. Many feeders keep feed in the troughs 
constantly, but more satisfactory results are secured when the steers 
are required to clean the troughs after each meal. An abundance of 
pure water and salt was provided all the time. 

At the close of the test the cattle were shipped to the Louisville 
market for sale. The experimental farm was located four miles from 
Whitfield, Ala., the nearest railroad station, and the cattle were 
driven to that point to be loaded on the cars. 

PRICE AND CHARACTER OF FEEDS. 

In work of this character the financial statement is not as satisfac- 
tory as could be wished, because the prices of feed as well as of cattle 
fluctuate considerably from year to year. Therefore the financial 
outcome of a particular experiment may not be duplicated by the 
cattle feeder owing to the different conditions under which he is 
operating. The prices listed in this bulletin were the actual prices 
paid for the feeds (except what was raised on the farm) and the actual 
prices realized for the cattle. This test was conducted during the 
winter of 1909-10 ; prices have not changed materially since that date. 
The following were the prices of the feeds, that produced on the farm 
being estimated at local rates: 

Per ton. 

Cottonseed meal $26. 00 

Cottonseed hulls. 7. 00 

Johnson-grads hay 11. 00 

Silage (produced on farm) 2. 50 

All of the above feeds were of good quality. The Johnson-grass 
hay had been cut at the proper stage and was of excellent quality. 
The cattle ate it with considerable relish. The silage, after the first 
few days, was also of good quality as far as brightness and taste were 
concerned. The com from which the silage was made did not have 
a heavy development of ear as the stand was thick and the planting 
was not made until June. Probably 30 bushels of com to the acre 
would have been secured if it had been gathered. The cottonseed 
meal was fresh, bright, and of a^high grade. 

PRELIMINARY FEEDING. 

Some of the steers were bought as early as November 1, 1909. Mr. 
Derby was getting his cattle together for winter feeding, so the 
experimental steers were placed in the feed lots with the general herd 
of feeding cattle until conditions were ready for the experiment to 



12 



FEEDINQ BEEF CATTLE IN ALABAMA. 



begin. On November 6 the cattle were all started on a small amount 
of cottonseed meal and hulls. This amount was gradually increased 
and they were receiving a full ration of the meal and hulls by 
November 15. This full feeding of cottonseed meal and hulls was 
continued until the experimental work began. On December 1 the 
60 steers to be used in the experimental work were selected from the 
general herd of probably 300 steers; they were divided into threelots 
of 20 steers each, tagged, weighed, and placed in their respective 
fields, and the experiment proper was begun. The period previous 
to December 1 was considered a preliminary period. This period was 
introduced so that the cattle would have an opportunity to become 
accustomed to the surroundings and the feeds before the inaugura- 
tion of the test. 

DAILY RATIONS. 

Many farmers injure their cattle and get them *'off feed'* by 
increasing too rapidly the cottonseed-meal part of the ration. These 
cattle had been in a preliminary feeding period for 24 days before the 
real test began, yet each steer was fed only 4 pounds of cottonseed 
meal daily at the inauguration of the experiment, December 1. Of 
course the amount was increased from time to time as the cattle 
would take it without scouring, but at no time did the steers receive 
more than 8 pounds of cottonseed meal daily. Many farmers would 
have had these steers on a daily ration of 10 pounds of cottonseed 
meal within 10 days after the feeding began. Scours, dizziness, still- 
ness, and occasional cases of blindness are almost sure to follow a 
heavy feeding of cottonseed meal. In the event of such troubles 
occurring the feeder is often compelled to sell under unfavorable 
circumstances, as the steers can not be held profitably. When they 
are marketed under such circumstances, the buyer is almost sure to 
discriminate against them because of their poor condition, and they 
consequently sell at a disadvantage when oiTered to the packer or 
butcher. 

The following table outline^, by periods of 28 days each, the 
amount of feed given each steer daily: 

Table 1. — Average daily ration for each steers by 28-day periods. 







Lotl. 






Lot 2. 




Lot 3. 


Period 


Cotton- 
seed meal. 


Cotton- 
aoed hulls. 


Com 

fldlflge. 


Cotton- 
seed meal. 


Cotton- 
seed hullSL 


Johnson- 

KTSBB 

nay. 


Cotton- 
seed meal. 


Cotton- 
seed huUs. 


First 28 days 

Second 28 cm vs.. 
Third 28 days... 


Pounds. 
4.64 
6.00 
7.73 


Pounds. 

14. S8 

15. 27 
24. 71) 


Pounds. 

22. fi? 
19. 49 
(') 


Pounds. 
4.64 
6.00 
7.73 


Pounds. 
13.58 
15.11 
14.21 


Pounds. 
9.43 

8.87 
7 03 


Pounds. 
4.64 
6.00 
7.73 


Pounds. 
26.53 
29.43 
23.96 



*■ No silago fed during this period. 



WINTEB FATTENING OP STEEKS. 13 

During the first 28 days each steer received an average of only 4.64 
pounds of cottonseed meal each day. The cattle feeder would not, 
as a rule, expect to secure good gains when the daily allowance of 
cottonseed meal was only 4.64 pounds, but the data show that these 
animals made excellent gains during the first 28 days. During the 
first period each steer in lot 1 (the silage-fed lot) received 14.88 
pounds of cottonseed hulls and 22.57 pounds of corn silage each day 
along with the 4.64 pounds of cottonseed meal. The cottonseed meal 
was sprinkled over the hulls and silage and thoroughly mixed by 
hand. During the first period of 28 days each steer in lot 3 (the lot 
to which nothing was fed except cottonseed meal and hulls) ate 26.53 
pounds of cottonseed hulls along with the 4.64 pounds of meal. At 
the end of the test, when the cottonseed meal was increased to 7.73 
pounds daily for each steer, as many pounds of hulls were not con- 
sumed as at the beginning, so the daily allowance was cut down to 
23.96 pounds for each steer. In lot 2 (the lot in which Johnson-grass 
hay was used to supplement the cottonseed meal and hulls) each 
steer, during the first period, ate 13.58 pounds of hulls and 9.43 
pounds of the hay each day along with the 4.64 pounds of cottonseed 
meal. They were given as much hay each day as they would clean up. 
The hay was fed in racks, and none of it was trampled under foot and 
wasted. 

During the second period of 28 days each steer ate an average of 6 
pounds of cottonseed meal each day. With the exception of a small 
increase the roughage part of each ration was maintained practically 
as it was in the first period. Each steer in lot 3 ate practically 30 
poimds of cottonseed hulls each day. The average cattle of the 
South, which are not as large as the ones used in this test, will not 
consume 30 pounds of hulls per steer per day. In some former beef- 
feeding work done by this Bureau and the Alabama Experiment 
Station* steers which averaged 816 pounds in weight at the close of 
the test ate only 19.9 pounds of cottonseed hulls daily. 

Unfortunately for the test and the cattle, the supply of silage 
lasted only 56 days, so no silage was fed the steers in lot 1 during the 
last period of 28 days. Cottonseed hulls replaced the silage. During 
the last period each steer ate 7.73 pounds of cottonseed meal daily. 
They would have eaten a larger amount if it had been placed before 
them. The roughage part of the ration was decreased as the amount 
of cottonseed meal was increased. The steers themselves regulated the 
amount of roughage, as they were given only as much as they would 
clean up at each meal. 

The above table should be closely studied by the cattle feeder. 
There is no doubt that the average southern farmer feeds too much 

' 1 See Bureaa of Animal Industry Bulletin 103. 



14 



FEEDIKG BEEF CATTLE IK ALABAMA. 



cottonseed meal to his fattening cattle. When the allowance of meal 
is kept down to a reasonable amount, the cattle will feel better and 
make gains more economically than when 9 to 10 pounds are fed to 
each steer daily. At the same time the owner will not be forced to 
sell at unfavorable times because of scours and sickness. 

DAILY AND TOTAL GAINS. 

The gains as given here are not fictitious in any sense. No ''fill'' 
is included, as the cattle had been on feed for 24 days before the test 
began. The gains would have been considerably larger if the "fill" 
had been included. 

Table 2. — Average weights and gains, 

[Dec. 1, 1909, to Feb. 23, 1910, 84 days.] 



Lot. 


Number 
of steers. 


Ration. 


Average 

InitiS 
weight of 
each steer. 


Average 

final 
weight of 
each steer. 


Average 

total gain 

of each 

steer. 


Average 

daily gain 

of each 

steer. 


1 
2 


20 
20 

20 


Cottonseed meal, cottonseed halls, corn silage. . 
Cottonseed meal, cottonseed hulls, J<dinson- 
grass hay 


Pounds. 
811 

820 
851 


Pounds. 
962 

949 
995 


Pounds. 
151 

129 
144 


Pounds. 
1.80 

1.54 


z 


Cottonseed meal, cottonseed hulls 


1.71 









RESULTS FOR FIRST 56 DAYS-WHILE SILAGE WAS FED. 



1 
2 



20 
20 

20 



Cottonseed meal, cottonseed hulls, com silage . 
Cottonseed meal, cottonseed hulls, Johnson 

grass hay 

Cottonseed meal, cottonseed hulls 




All of the cattle made satisfactory but not unusual gains. In the 
first part of Table 2 it is seen that the silage-fed steers (lot 1) made 
the largest gains, making an average daily gain of 1.8 pounds per 
steer for the whole period of 84 days. In the lower part of Table 2 
are found the results of the first 56 days of the test, or the period 
when com silage was fed to the cattle in lot 1. When the second part 
of the table is studied, it is seen that the cattle which ate silage did 
not make as large daily gains as did those which were fed nothing but 
cottonseed meal and hulls. During the first 56 days each steer in 
lot 1 (the silage lot) made an average daily gain of 1.86 pounds, while 
during the same period each steer in lot 3 (cottonseed meal and hulls 
only) gained 1.89 pounds each day. However, the reader should not 
come to the conclusion that the daily gains measure the success of a 
feeding operation altogether. It is, of course, necessary for good 
gains to be secured, but the final profits are not determined entirely 
by the daily gains. Other factors, such as the price of the feeds and 
the selling price of the cattle, must be taken into consideration. 



WINTER FATTENING OP STEERS. 15 

The cattle which were fed a partial ration of Johnson-grass hay 
made the least satisfactory gains, making a daily gain per steer of 
only 1.54 pounds during the whole period of 84 days. As far as gains 
were concerned, the Johnson-grass hay proved to be unsatisfactory, as 
cottonseed meal and hulls produced greater gains when fed alone 
than when the two were combined with Johnson-grass hay. The 
hay was of good quality and the cattle ate it with considerable relish. 
Oftentimes Johnson grass is cut at such a late stage of maturity that 
it is stiff, woody, and unpalatable, but the hay used in this test was cut 
and harvested at the proper stage. 

The supply of silage was exhausted at the end of 56 days, so this 
lot of cattle (lot 1) was continued to the end of the test on cottonseed 
meal and hulls, the hull part of the ration being increased sufficiently 
to take the place of the silage. After the feeding of silage was 
discontinued the cattle still continued to make good gains, as each 
steer made a gain of 47 pounds during the last 28 days of the test. 
During this same period each steer which was eating Johnson-grass 
hay Got 2) made a gain of 49 pounds, while each steer in lot 3 gained 
only 38 pounds. As a matter of fact, it was expected that but 
small gains would be secured after the discontinuance of the silage, 
but the change was made gradually and the steers did not seem to 
notice the substitution of huUs for the silage. Cottonseed meal and 
hulls make an extremely palatable combination of feeds; in fact, 
it is difficult to find a combination of feeds more palatable than a 
mixture of these two southern feeds. 

At the end of the experiment the steers in lots 1, 2, and 3 averaged 
962, 949, and 995 pounds, respectively, in weight; they made average 
total gains per steer of 151, 129, and 144 pounds in the respective 
lots. 

QUAHTITY AND COST OP FEED REQUIRED TO MAKE loo POUNDS 

GAIN. 

In work of this character the real value of a feed, or a combination 
of feeds, is measured by the number of pounds of feed required to 
make 100 pounds of gain in live weight. With this information the 
fanner can apply the knowledge to his own conditions and quickly 
determine what it would cost to make 100 pounds of gain on his own 
farm. The table following shows the quantity of feed required 
to make 100 pounds of increase in Uve weight and the cost of the 
gains under the conditions of this test. The price placed upon the 
feeds was their actual cost laid down on the farm. The silage, of 
course, was made on the farm, and on it was placed an estimated 
value of $2.50 a ton. 



16 



FEEDING BEEF CATTLE IN ALABAMA. 



Table 3. — Quantity and co$t o/feed required to make 100 pounds of gain. 

[Dec 1, ig09, to Feb. 23, 1910, 84 days.] ' 



LoL 



Ration. 



8 



Cottonseed meal. . 
Cottonseed hulls. . 

Comsila^ , 

Cottonseed meal . . , 

Cottonseed hulls. . , 

Johnson-fH^ass hay . 

'Cottonseed meal. . 

\Cottonseed huUs. . 



Feed to 

make 100 

pounds 

of gain. 



Coat of feed 
to make 

lOOjpounda 
oigain. 



Pommdi. 
341 

1,020 
781 
399 i 
931 
fiSO 
367 

l,fiM 






$8.98 

U.47 
10.06 



RetuUsfor firtt 56 dayt—^kile Mlage was fed. 



1 

2 
8 



Cottonseed meal . . . 

Cottonseed hulls. . . 

Com silage 

Cottonseed meal. . . 

Cottonseed hulls. . . 

Johnson-grass hay . 
rCottonseed meal . . , 
ICottonseed hulls. . . 




87.96 

11.88 
8.80 



When feeds are valued as previously stated it is seen that the 
silage-fed steers Got 1) made the cheapest gains in both cases. When 
the whole period of 84 days is taken into consideration each 100 
pounds of increase in live weight cost $8.98 when the silage was 
used, $11.47 when Johnson-grass hay supplemented the cottonseed 
meal and hulls Got 2), and $10.08 when nothing was fed except 
cottonseed meal and hulls Got 3). Johnson-grass hay proved to be 
the most expensive and unsatisfactory feed used. During the first 
56 days, when silage was being fed, each 100 pounds of gain in 
lot 1 cost $7.98; the same gain cost $11.88 in lot 2 where Johnson- 
grass hay was used in place of silage, and $8.80 in lot 3 where cotton- 
seed meal and hulls were fed alone. As far as economical gains were 
concerned the silage proved to be a valuable addition to the cotton- 
seed meal and hulls, but money was lost when Johnson-grass hay 
replaced part of the cottonseed hulls, each 100 pounds of increase in 
weight costing just $3.08 more when the hay was fed than when 
cottonseed meal and hulls were fed alone. 

By studying the second part of Table 3, it is seen Got 1) that 287 
pounds of cottonseed meal, 812 pounds of hulls, and 1,132 poimds of 
silage produced 100 pounds of increase in weight. When the meal 
and hulls were fed alone Got 3) it is further seen that 280 pounds of 
meal plus 1,475 pounds of hulls produced the same number of pounds 
of increase in weight; therefore 1,132 pounds of silage saved 663 
pounds of hulls, but at the same time caused the loss of 7 pounds of 
cottonseed meal; or, 1 ton of the silage actually saved $3.94 worth 
of hulls and cottonseed meal when hulls and meal were valued at 



WINTEB FATTENING OP STEERS. 17 

$7 and $26 a ton, respectively. Com silage in tliis test was therefore 
worth $3.94 a ton. In the same way it is found that 641 pounds of 
Johnson-grass hay. took the place of 471 pounds of hulls, but caused 
the loss of 92 pounds of cottonseed meal; or, 1 ton of hay proved to 
have a feeding value of only $1.31 when the meal and the hulls were 
valued as above. Johnson-grass hay in this test was therefore worth 
$1.31 a ton, whereas it cost $11 a ton. Ton for ton, silage was just 
three times as valuable as Johnson-grass hay when they were both 
used along with cottonseed meal and huUs for fattening cattle. 
Johnson-grass hay proved to be a poor feed for fattening purposes, 
while silage had an exceedingly hi^ value when used for the same 
purpose. The cattle feeder can not, therefore, a£Pord to use Johnson- 
grass hay along with cottonseed meal and hulls for fattening pur- 
poses, and this experiment tends to show that the majority of southern 
feeders can not use a more economical feed than sil^e for this purpose. 

ADVANTAGES OP USING PURCHASED FEEDS. 

The majority of our southern farmers object to buying cottonseed 
meal, hulls, and other feeds for beef cattle on the ground that the 
original prices of the feeds can not be realized after being fed to cattle. 
At the same time thousands of these same farmers buy cottonseed 
meal and use it as a commercial fertilizer, when experience and experi- 
ments all teach that the first use of the meal should be as a feed for 
some kind of live stock and the second use as a fertilizer in the form 
of barnyard manure. When the cottonseed meal is fed to live stock 
it is used twice, once as a feed and again as a fertilizer. Many of 
our best farmers feed cattle for no other reason than to obtain the 
barnyard manure, and are satisfied if they come out even on the 
cattle; the manure is well worth the expense of feeding. 

In these experiments the cottonseed meal cost $26 a ton and the 
huUs $7 a ton, and we are satisfied that in every case these feeds 
realized, as a result of feeding to the cattle, much more than they 
cost; that is, an actual profit was made on each ton of the feeds and at 
the same time the manure was left on the farm. The meal and hulls, 
therefore, were no expense at all to the soil or to the succeeding crops. 

VALUE OP BARNYARD MANURE. 

The farmer who has lands which should be built up should feel 
that he has fed cattle at a profit when manure is obtained free above 
all other expenses, as this manure has an exceedingly high fertilizing 
value. Beef cattle should be more generally introduced because 
of the good they do in building up and maintaining soils. Under 
the present system of cotton farming the soils are becoming poorer 
and poorer. With the introduction of cattle the soil will begin to be 

64012*»— BuU. 159—12 3 



18 FEEDING BEEF CATTLE IN ALABAMA. 

built up. Director Thome, of the Ohio Agricultural Experiment 
Station, has been making tests with barnyard manure for several 
years, appljring the manure upon a plot of ground upon which was 
running a three years' rotation of com, wheat, and clover. Eight 
tons of manure an acre were appUed. The average yearly increase 
an acre, following the one application, was as follows: 

Com, 14.7 buflhelSi at 70 centa a bushel $10. 29 

Com stover, 744 pounds, at |6 a ton 2. 23 

Wheat, 8.36 bushels, at $1 a bushel 8. 36 

Wheat straw, 897 pounds, at $4 a ton 1. 79 

Clover hay, 686 pounds, at |12 a ton 4. 12 

Total value of 8 tons of manure 26. 79 

Total value of 1 ton of manure 3. 35 

He further states (Bulletin 183, Ohio Experiment Station) that the 
value of farm manure can be materially increased by balancing the 
manure with the addition of a carrier of phosphorus. The farm 
manures are too high in nitrogen as compared with the other elements. 
By balancing stable manure, the value of 8 tons was increased 
$12.20 after deducting the cost of the material used for the balancing 
of the manure. This is $1.53 a ton, and when added to the $3.35 
above, brings the total possible value of each ton of manure up to 
$4.88. During a feeding period of 100 days each steer will produce 
at least 1^ tons of manure. This profit should be added to the 
feeding or direct profits. 

The Arkansas Station (Bulletin 68) made a test to determine the 
value to each succeeding crop of growing peas in the corn, gathering 
the com, and then grazing both the peas and the stalks by the steers. 
The steers were fed some cottonseed in addition to the grazing. As 
the result of this crop of peas and the grazing, the succeeding cotton 
crop was increased 626.5 pounds of seed cotton over the area where 
com alone had been grown. A third lot was planted to com, and the 
increase in com, due to the pea crop and the grazing, was 14 bushels 
an acre. 

FINANCIAL STATEMENT. 

It must be remembered that the financial statements in this bulletin 
are based on the local conditions where the feeding was carried on. 
Should the conditions elsewhere be different, the results will also differ. 
The price of the cattle when put into the feed lot is one very variable 
factor. The feeders in this particular experiment cost 3} cents a 
pound. In another part of the State they might have cost more 
than they did in Sumter County, and in still a third part they might 
have cost considerably less. The financial statement will not be 
misleading if the reader bears in mind that it does not apply to all 
conditions. 



WINTEB FATTENING OF STEERS. 19 

The cattle, as previously noted, were bought m Sumter and neigh- 
boring counties for 3} cents a pound during the fall of 1909. They 
were fed on cottonseed meal and cottonseed hulls for 24 days before 
the test began. The test continued for 84 days, when the cattle 
were ready for sale and were shipped to the Louisville (Ky.) market, 
where all of the steers sold for $5.75 a hundredweight. It cost 65 
cents a hundredweight to ship them to the market, so they are 
estimated in the financial statement at $5.10 a hundredweight. The 
$6.10 represents the price actually received on the farm. 

Lot 1. Cottonseed meal, cottonseed hulls, com silage: 

By sale of 20 steeis, 18,658 pounds, at $5.10 x>er hundredweight $951. 6C 

To 20 steers, 16,220 pounds, at SJ cente a pound $527. 15 

To 10, 290 pounds cottonseed meal, at $26 a ton 133. 77 

To 30,768 pounds cottonseed hulls, at $7 a ton 107. 69 

To 23,554 pounds com silage, at $2.50 a ton 29. 44 

Total expense 798. 05 

Total profit 153.61 

Profit per steer 7. 68 

Lot 2. Cottonseed meal, cottonseed hulls, Johnson-grass hay: 

By sale of 20 steers, 18,411 pounds, at $5.10 per hundredweight 938. 96 

To 20 steers, 16,400 pounds, at 3} cents a pound $533. 00 

To 10,290 pounds cottonseed meal, at $26 a ton 133. 77 

To 24 ,026 pounds cottonseed hulls, at $7 a ton 84. 09 

To 14,185 pounds Johnson-giass hay, at $11 a ton 78. 02 

Total expense 828. 88 

■I '■ ■ « 

Total profit 110.08 

Profit per steer 5. 50 

Lot 3. Cottonseed meal, cottonseed hulls: 

By sale of 20 steers, 19,303 poimds, at $5.10 per hundredweight 984. 45 

To 20 steers, 17,020 pounds, at 3} cents a pound $552. 15 

To 10,290 pounds cottonseed meal, at$26a ton 133.77 

To 44,755 pounds cottonseed hulls, at $7 a ton 159. 09 

Totil expense 845. 01 

Total profit 139.44 

Plx)fit per steer 6. 97 

The foregoing financial statement shows that all of the lots of 
steers were fed at a profit. The outcome was satisfactory. The 
greatest profit was made in lot 1, where silage was used. The smallest 
profit was made in lot 2, where the Johnson-grass hay was fed. The 
cattle in lots 1 and 3 sold at the same price and made practically 
the same total gains in Uve weighty but those in lot 1 had the advaa- 
tage in that they had a cheap feed — silage — ^added to the basal ration 
of cottonseed meal and hulls. Each steer in lot 1 made a clear 
profit of $7.68; while each one in lot 3 made a profit of only $6.97. 
The steers which received Johnson-grass hay along with the cotton- 
seed meal and hulls (lot 2) made a profit of only $5.50 each. 



20 



FEEDING BEEF CATTLE IN ALABAMA. 



SLAUGHTER DATA. 

Table 5 shows the total weight of each lot of cattle alter allowing 
3 per cent for shrinkage^ the live weight at the Louisville market, the 
number of pounds each steer lost in shipment, the dressed weight at 
Louisville, and the per cent of dressed weight to live weight. The 
steers were driven 4 miles to a railroad, and, on account of delays, 
were in the cars 48 hours. 







Table 5. 


—Skipping 


weights and slaughter record \ 




Lot. 


Number 

of 
steers. 


Total 

weight 

on farm. 


Total 
weight at 
Louisville. 


Average 
shrinkage 
per steer. 


Total 

dressed 

weif ht at 

Louuville. 


Average 
percent 
dressed 
oat by farm 
weights. 


Average per 

centdreased 

out by 

market 

weights. 


1 
2 
3 


Pounda. 
20 • 19,235 
20 1 18.980 
20 1 19,900 


Pounda. 
17,685 
17,615 
18,325 


Pounda. 

77.5 
68.3 

78.8 


Pounda. 
9,926 
9,736 
10.164 


5L6 
61.3 
51.1 


56.1 
55.3 
55.5 



The shrinkage on the road was rather great, but it should be 
remembered that there was a delay of several hours in shipment. 
Those cattle which were fed Johnson-grass hay Qot 2) lost the fewest 
pounds in weight. Each steer lost 77.6, 68.3, and 78.8 pounds in 
lots 1, 2, and 3, respectively; or, the silage-fed steers flot 1) lost in 
transit 8.1 per cent of their weight, those in lot 2 (Johnson-grass lot) 
lost 7.1 per cent, while those in lot 3 (cottonseed meal and hulls) 
shrunk 7.9 per cent. 

The steers in lot 1 (the silage-fed cattle) dressed out higher than the 
steers in lots 2 and 3, dressing 56.1 per cent by the market weights. 
The steers in lots 2 and 3 dressed, respectively, 55.3 per cent and 55.5 
per cent. 

SUMMARY. 

Table 6. — Summary of results. 



Item. 



Average weight of steers at beginning, Dec. 1, 1909 

Average weight of steers at close. Feb. 23, 1910 

Average total gain of each steer for whole period of 84 days 

Average daily gain of each steer for whole period of 84 days 

Average daily gain of each steer for first 56 days while silage was fed. 

Average cottonseed meal fed daily per steer 

Average cottonseed hulls fed daily per steer 

Average silage fed dnily per steer 

Average Johnson-grass hay fed daily per steer 

Cottonseed meal to make 100 pounds gain for whole period of 84 days. 
Cottonseed meal to make 100 pounds gain for first d6 days 



Lotl.— 
Feed: Cot- 
tonseed 
meal, cot- 
tonseed 
hulls, com 
silage. 



Pounda. 
811 
962 
151 
1.8 
1.86 
6.1 
15.1 
21 



Rooghage to make 100 pounds gain for whole period of 84 days. 
Roui 



ouehageto 



make 100 pounds gain for first 56 days while silage was 



Cost to make 100 iKmnds gain for whole x>er(od of 84 days . 

Cost to make 100 pounds gain for first 56 days 

Cost of steers per nundredwelght in fall 

Selling price of steers in Louisville 

Selling price of steers on farm 

Profit per steer 




Lot2.— 
Feed: Cot- 
tonseed 
meal, cot- 
tonseed 
hulls, John- 
son-grass 
hay. 



Pounda, 
820 

129 
1.54 
1.43 
6.1 
14.3 



8.40 
399 
372 
>931 
«550 
U.004 
»64l 
DoUara, 
11.47 
U.88 
3.25 
5.75 
5.10 
5.50 



Lots.— 
Feed: Cot- 
tonseed 
meal, oot« 
tonseed 
hulls. 



Pounda, 

851 

995 

144 
1.71 
1.8» 
6.1 
26.6 



357 

280 

11,564 

M.475 

Poltert. 

10.08 
8.80 
3.25 
5.75 
5.10 
6.97 



Silage. 



s Hulls. 



Hay. 



WINTEB FATTENING OP STEERS. 21 

1. The steers which were used in tliis test were from 2 to 3 years 
old. They had all been graded up by the use of Aberdeen-Angus 
Hereford, and Shorthorn sires. 

2. At the beginning of the test they averaged 827 pounds in weight. 
They were fed 84 days, and at the close of the test they averaged 967 
pounds. 

3. The 60 head of steers were divided into three lots and fed as 
follows: 

Lot 1: Cottonseed meal, cottonseed hulls, com silage. Lot 2: 
Cottonseed meal, cottonseed hulls, Johnson-grass hay. Lot 3: Cot- 
tonseed meal, cottonseed hulls. 

4. For the whole period of 84 days average daily gains of 1.8, 1.54, 
and 1.71 pounds were secured in lots 1, 2, and 3, respectively. 

5. During the first 56 days, when silage was fed in lot 1, average 
daily gains of 1.86, 1.43, and 1.89 pounds were secured in lots 1, 2, 
and 3, respectively. 

6. For the whole period of 84 days it cost $8.98, $11.47, and $10.08 
to make 100 poimds of gain in lots 1, 2, and 3, respectively. 

7. For the first 56 days, when silage was fed in lot 1, it cost, respec- 
tively, $7.98, $11.88, and $8.80 to make 100 pounds of gain in lots 1, 
2, and 3. 

8. Li the fall of 1909 the steers cost $3.25 per hundredweight. At 
the end of the test they were shipped to Louisville and sold for $5.76 
per hundredweight. 

9. Each steer in lots 1, 2, and 3 netted a clear profit of $7.68, $5.50, 
and $6.97, respectively. 

10. Com silage proved to be an exceedingly satisfactory addition 
to a basal ration of cottonseed meal and hulls, but Johnson-grass 
hay was an exceedingly unsatisfactory supplement when used in the 
same way. 



n. WINTERING STEERS FOLLOWED BT SUMMER FATTEN- 
ING ON PASTURE. 



INTRODUCTION. 

For several years this bureau, cooperating with the Alabama 
Experiment Station, has been studying the subject of wintering 
mature steers and subsequently fattening them in the summer on 
pasture. Some of the work has been published/ but the conditions 
surrounding the work herein published were altogether different from 
those of the previous work. In the first place, these cattle were of 
different age and quality from the ones used in the former experi- 
mental work. In the second place, the grass upon which these cattle 
grazed grew on a sandy instead of a lime soil. In the previous work 
the cattle were grazed upon lime soils with sweet clover (Melilotus) 
as the basal pasture crop during the early part of the grazing season. 
In the work published in this bulletin no sweet-clover pastiu-es were 
available, as sweet clover does not occur upon the sandy soils of this 
region. 

Two separate experiments are reported in this part of the bulletin, 
owing to the fact that two distinct types of cattle were used. The 
animals were divided into four lots, two of them composed of high- 
grade young cattle and the other two of common or scrub cattle 
fully a year older. The work was done in cooperation with Mr. F. I* 
Derby, of Sumter County, Ala., he fumisliing the cattle and the feed 
and the Bureau of Animal Industry and the Alabama Experiment 
Station providing a trained man to carry on the experiment. Mr. 
J. W. Ridgway was located on the farm and had personal supervision 
of all of the experimental work. 

OBJECT OF THE WORK. 

This work was outlined with the following objects in view: 

1. To study the problem of feeding steers during the winter months 
with a view to fattening them on pasture the following summer. 

2. To determine the profits, if any, in supplementing sandy-soil 
pastures with cottonseed cake during the summer fattening process. 

3. To study a common southern method of managing and fattening 
common or scrub cattle. 

1 See Bureau of Animal Industry Bulletin 131. 
22 



STJMMEB FATTENING ON PASTUBE. 23 

Steers can be purchased cheaper durmg the fall of the year than at 
any other time, so many feeders prefer to buy in the fall. Wlien cheap 
steers are so purchased, a common practice in the South is to "rough" 
them through the winter months as cheaply as possible, turn them on 
pasture the following summer, and sell them to the butcher at the 
end of the pasture season. 

THE CATTLE. 

The cattle were all bought in Sumter and neighboring counties, but 
those selected for lots 4 and 5 were an excellent grade of animals, all 
having Shorthorn or Aberdeen-Angus blood, while those placed in 
lots X and Y represented no particular breeding; they were, in fact, 
scrubs, or the common cattle of the neighborhood. The steers in 
lots 4 and 5 were from 20 to 24 months old when purchased, in the fall 
of 1909, and had attained an average weight of 616 pounds. The 
steers of lots X and Y were from 3 to 4 years old and weighed only 
565 pounds each when the tests began, December 6, 1909. The 
cattle, both young and old, were dehorned as soon as they were 
brought to the farm. 

The reader's attention should be called to the fact that while the 
results secured in lots 4 and 5 are comparable with each other, they 
are not in any way comparable with the results seciffed in lots X 
and Y. These are two separate experiments and are not comparable 
in any way. 

THE PASTURES. 

The soil upon which these steers grazed was of a sandy and sandy- 
loam character, such as is found in a cut-over pine district. A large 
proportion of the pastures were low, so that in rainy weather they 
became exceedingly wet. There was some sandy ridge land, however, 
in each pasture. 

Carpet grass, lespedeza, broom sedge, and a small amount of Ber- 
muda and Paspalum dUataium constituted the plants that formed the 
pastures. Sweet clover (Melilotus), as before stated, does not grow 
in this region. They afforded an abundance of grass throughout the 
grazing season, but the growth was rank and very watery, as the fre- 
quent rains kept the pasture exceedingly wet during the whole test. 
No expense or time had ever been expended on these pastures except 
to build a wire fence around them. The plants mentioned above had 
come volimtariJy after the pine woods were cleared away. 

THE WINTER RANGE. 

The steers of lots X and Y, after being dehorned and tagged, were 
turned out, December 6, 1909, in a tract of cut-over pine lands. 
Approximately 20;000 acres of land were in this tract, but it was not 
fenced, so the steers had the privilege of going practically anywhere 



24 



FEEDING BEEF CATTLE IN ALABAMA. 



in the southern part of Sumter County. This land had grown up 
during the previous summer with broom sedge, lespedeza, and other 
native grasses. When frost came the grasses were, of course, all 
killed, but still they afforded some grazing for the steers during the, 
first part of the winter. During the latter part of the winter, when 
grazing is usually short; no little amount of Augusta vetch came up 
and furnished good grazing during the early spring months. This 
plant, more than anything else, perhaps, kept the steers from losing 
weight while on the range, as it gave good grazing m March and April. 
The steers evidently gained in weight during these two months. The 
steers were not taken o3F this range until April 23, 1910. 

The young steers of lots 4 and 5 were not turned on the range. 

PLAN OF THE FEEDING. 

In order to give a clear idea of the nature of the work, the general 
plan of the feeding is outlmed below: 

Table 7. — General plan of the feeding. 

THE YOUNO STEERS. 









« 


Lot. 


Number 
of steors. 


Winter feeding. 


Summer tettenJng. 


4 
6 


18 
17 


(Dec. 6, 1000, to Mar. 31, 1010.) 

Cottonmed meal and cottonseed huUs (one-half 
ration). 

Cottonseed meal, oottonaeed haUs, and Johnson- 
grass hay (one>half ration). 


(Apr. 2 to Aug. 26, 1910.) 
Pasture and cottonseed cake. 
Do. 



THE COMMON STEERS. 



X 

Y 



28 
16 



(Dec. 6, 1009, to Apr. 23, 1910.) 



Range only. 
do 



(Apr. 23 to Sept. 2, 1910.) 

Pasture and cottonseed cake. 
Pasture alone. 



The general plan was to feed the steers of lots 4 and 5 sufficient 
feed to produce small gains throughout the winter nM>nths. They 
were a good class of cattle and young, so it was thought that it wotdd 
pay to feed them liberally during the winter months. Accordingly 
a partial ration of cottonseed meal and cottonseed hulls was fed to 
the steers in lot 4, and those in lot 5 had some Johnson-grass hay 
added to the basal ration of cottonseed meal and hulls. No effort 
was made to fatten these young cattle during the winter; the object 
was to make only small gains and keep them in thriving condition. 
The fattening was to occur the subsequent sunmier, when they were 
on pasture. 

The steers of lots X and Y were turned out as one lot on the range 
for the winter. These cattle being of poor quality, it was not thought 
profitable to give them high-priced feeds during the winter months. 



SUMMER FATTENING ON PASTURE. 25. 

when they were to be fattened on pasture the following summer. As 
stated before, the range consisted of cut-over pine lands; they had 
the freedom of probably 20,000 acres of land. 

The authors realize that this method of handling and feeding cattle 
during thQ winter is one that will soon go out of vogue on account of 
the fact that these large rang^ will eventually be settled and fenced, 
but at the present time and under present conditions many farmers 
are so situated that they can profitably make use of these lai^e tracts. 
These cattle received no attention at all throughout the winter months. 
In fact, only a few of them were seen during the whole winter. The 
following spring, March 21, they were brought up, weighed again, and 
turned onto the summer pasture for the summer fattening work. 
They were now divided into two lots and fed upon different feeds. 
The steers of lot X were grazed upon a pasture and received a small 
feed of cottonseed cake in addition to the pasture. The steera of lot 
Y were in a similar pasture and received nothing in addition. 

No shelter except the trees was provided for the cattle in either the 
winter or summer time. They did not seem to suffer from the cold 
in the winter or from the heat in the summer. The summer pastures 
were abundantly provided with good shade trees and water. 

While there were cattle ticks ( Margarojms annulatus) in the pasture, 
yet the cattle were not permitted to become badly infested. A 
dipping vat was used to keep down heavy infestation. No cases of 
Texas fever developed. 

The weight of each steer was secured at the beginning and the end 
of each test, and, with the exception of lots X and Y during the 
winter of 1909-10, the total weight of each lot was noted every 28 
days. When the steers were sold, they were driven 4 miles to the 
shipping point at Whitfield, Ala. 

CHARACTER AND PRICE OF THE FEEDS. 

Local conditions determine to a largo extent the farm prices of 
feeds. Any prices that might be assumed would not meet aU condi- 
tions, but the following prices have been taken as a basis upon which 
to make financial estimates : 

Cottonseed meal ........ .per ton. . |26. 00 

Cottonseed cake do 26. 00 

Cottonseed hulls do 7. 00 

Johnson-grass hay do H. 00 

Pasture, per steer per month. . . 50 

All of the feeds were of good quality." The cottonseed cake, which 
was used in all of the summer feeding work, had been broken into 
nut size by the.oil mill and sacked. As has been statediniL previous 
bulletin, this cake can be purchased in the large cake size, just as it 
comes from the press, for about S2 a ton cheaper than in the nut size. 

54012^— Bull. 159—12 4 



26 



FEEDIKG BEEF CATTLE IN AT.ARAMA, 



Some feeders find that it pays to break the cake on their own farms. 
The cake is the same thing as cottonseed meal, except that it is not 
groimd into a meal. There are several advantages in feeding cake 
in place of cottonseed meal, especially in summer feeding. A rain 
does not render the cake unpalatable ; but it will often put the meal 
in such a condition that the cattle will not eat it. Again, no loss is 
incurred with the cake during windy days, whereas the meal, when 
fed in the open pasture, is sometimes wasted on accoimt of the winds. 
Furthermore, the cake requires chewing before being swallowed, and 
therefore must be eaten very much more slowly than the meal, so 
when a number of steers are being fed together the greedy one has 
little chance to get enough cake to produce scours. In feeding cotton- 
seed meal the greedy steer often scours on account of the fact that he 
can bolt the meal and get more than his share; this not only injures 
the steer but makes the bimch ''feed out" unevenly. 

THE WINTER FEEDING. 
DAILY BATIONS. 

It should again be noted that the cattle were not being f att^ied 
during the winter months; they were simply being carried through so 
as to be in condition for fattening on grass the following summer. 
The steers of lots 4 and 5 were confined on cotton fields where cotton 
had been grown the previous summer. Of course they obtained some 
feed from these cotton fields, especially during the first part of the 
winter, and in addition were given a half ration of cottonseed meal, 
hulls, and hay, as noted below. Lots X and Y were on the open 
range, with no additional feed. The amount of feed given is shown 
in the following table: 



Table 8. — The average daily amount of feed given each eteer during the winter numthi. 

THE YOUNG STEERS. 
[Dec. 6, 1909, to Mar. 31, 1910, 116 days.] 



Lot. 



4 
5 



Number, 
ofsteen. 



18 
17 



Rati<ni. 



f GottoKueed meal. . 
\Cottonseed hulls.. 

1 Cottonseed meal. . 
Cottonseed hulls. . 
Johnson-giaas hay 



daily 
amount. 



2.88 
18.99 
2.86 
6.82 
6.60 



THE COMMON STEERS. 
[Dec. 6, 1909, to Apr. 28, 1910, 180 days.] 



SUMMER FATTENING ON PASTURE. 



27 



It is seen that none of the steers was fed more than a half ration of 
purchased feeds. Each steer in lot 4 received an average daily feed 
of 2.35 pounds of cottonseed meal plus 13.29 poimds of hulls. Each 
steer in lot 5 consumed an average of 2.35 pounds of cottonseed 
meal, 6.82 pounds of cottonseed hulls, and 5.5 pounds of Johnson- 
grass hay daily. These were small amounts of feed, but, as will be 
seen later, the animals made a fairly good daily gain. During the 
whole winter each animal in lot 4 ate 273 pounds of cottonseed meal 
and 1,542 pounds of hulls at a total cost of S8.95. During the same 
length of time each steer in lot 5 ate 273 pounds of cottonseed meal, 
791 pounds of huUs, and 638 pounds of hay, at a cost of $9.83. 

The steers in lots X and Y received no feed at all in addition to the 
cut-over pine range. 

WEIGHTS AND GAINS DURING WINTER MONTHS. 

The following table shows that all of the cattle gained during 
the winter months, even the ones which were turned out on the open 
range and received no feed or attention during the whole winter. 
In this connection it should be called to mind that these cattle which 
were turned out on the range were mature animals. They were 
better able than young animals to care for themselves, as they were 
strong enough to get about over large areas and hunt for a living. 
These mature steers can withstand careless treatment and yet come 
through to spring in fairly good condition, while young animals, like 
those in lots 4 and 5 might starve with similar feed and treatment. 
No one would advise a farmer to turn young animals on an open 
range during the winter months and give them no feed or attention. 
A young beef animal, if he is to attain a respectable size, must be fed 
and cared for during the cold months. 

Tablb 9. — Weights and gains during the winter months, 

THE YOUNG STEERS. 
[Dec. 6, 1909, to Mar. 31, 1910, 116 days.] 



Lot. 


Number 
ofsteen. 


Ration. 


Average 

initiia 

weight of 

each steer 

(Dec. 6, 

1909). 


Average 

spring 

weight of 

each 8t4Wr 


Average 

total gain of 

each steer. 


Average 

dailvgainof 

each steer. 


4 


18 
17 


Cottonseed meal and cottonseed hulls 
(on^half ration)... 


Pounds. 
624 

608 


Pounds. 
696 

676 


Pound*. 

74 

66 


Pounds. 
0.64 


B 


Cottonseed meal,' cottonseed hulls, 
Johnson-grass hay (one-half ration) . 


.59 



TUE COMMON STEERS. 
[Dec. 6, 1909, to Apr. 23, 1910, 139 days.] 



X 

Y 



) « 



Range alone. 



565 



«575 



10 



.08 



« Apr. 23, 1910. 



28 



FEEDING BEEF CATTLE IN ALABAMA. 



The steers in lots 4 and 5 made as good gains as was desired. No 
effort was made to fatten them. During the whole feeding period of 
116 days each steer in lots 4 and 5 gained an average ol 74 and 68 
poimds, respectively. They were in excellent condition when spring 
came. 

Each steer in the range lots (lots X and Y combined) gained an 
average of 10 pounds during the whole winter. They, too, were in 
good condition when grass came in the spring. When cattle are turned 
onto the open range during the winter, as a rule, they lose instead 
of gain in weight. In some former work the cattle which had no feed 
during the cold months except what they secured from the open range, 
lost approximately 100 pounds each during the winter time,* but 
some allowance should be made for the fact that they came oflF the 
range several weeks earlier than lots X and Y. It is, however, a very 
imusual occurrence for steers to make gain during the winter months 
when handled and fed as were those in lots X and Y. 

QUANTITY AND COST OP FEED REQUIBED TO MAKE 100 POUNDS GAIN 

DURING THE WINTER. 

The following table shows that the gains made during the winter 
months by the steers in lots 4 and 5 were expensive ones. There 
is no way to determine the cost of gains made by the range cattle 
(lots X and Y) as no value or rental price has ever been placed upon 
the open range. 

Table 10. — Quantity and co t of feed required to make 100 pounds of gain during the 

V inter month \ 

THE YOUNG STEERS. 
[Dec. 0, 1909. to Mar. 31, 1910, 116 days.] 



Lot. 



Ration. 



4 



/Cottonseed meal, . 
Cottonseed hulls. . 
Cottonseed meal. . 
Cottonseed hullK. . 
Johnson-tTass hay . 



Feed required 

to make 100 

pounds of 

gain. 



Cost of feed 

to make 100 

pounds of 

gain. 




$12.05 
14.71 



THE COMMON STEERS. 
[Dec. 6, 1909, to Apr. 2.3, 1910, 139 days.] 



Y JRange alone. 



Nothing. 



Each 100 pounds of gain during the winter months cost $12.05 and 
$14.71 in lots 4 and 5, respectively. These were very expensive gains 



^ Bureau of Animal Industry Bulletin 131. 



SUMMER FATTENING ON PASTURE. 29 

and hard to overcome, even when the steers were continued on a very 
cheap ration — ^pasture and cottonseed cake — the following summer. 
In fact, the expensive winter gains of lots 4 and 5 were never counter- 
acted by the cheap gains of the following summer, as money was 
finally lost on these two lots of cattle. The gains secured during the 
winter months were expensive by reason of the fact that the ration 
was too near a mere maintenance ration. It is seen that in lot 4 
368 pounds of cottonseed meal plus 2,077 pounds of hulls were 
required to make 100 pounds of increase in live weight. In lot 6' 
where Johnson-grass hay was introduced, 424 pounds of cottonseed 
meal, 1,160 pounds of hulls, and 936 pounds of hay were required to 
make 100 pounds of gain. 

Johnson-grass hay did not improve the ration of cottonseed meal 
and hulls. Nothing was gained by the introduction of the hay. In 
comparing the results of lots 4 and 5 it is learned that 935 pounds of 
Johnson-grass hay saved 917 pounds of hulls, but caused a loss of 56 
pounds of cottonseed meal; or, 1 ton of the hay was worth $5.26 in 
this feeding test, when cottonseed meal and cottonseed hulls are 
valued at $26 and $7 a ton, respectively. It will be remembered that 
in Part I of this bulletin the same hay was worth only $1.31 a ton as 
a fattening feed. (See p. 17.) The nearer a feed or a combination of 
feeds approaches a mere maintenance ration the more valuable such 
a hay as Johnson grass becomes. 

The small increase in live weight of the steers in lots X and Y was 
made without cost, as the range, their only feed, was free. 

THE SPRING COST OF THE STEERS. 

The steers in lots 4 and 6 cost 3 J cents a pound in the fall of 1909; 
those in lot 4 averaged $21.84 each and those in lot 5 $21.28. They 
were well-bred animals ; no scrubs were among them. The steers in 
lots X and Y were of a very conmion grade and cost only 2 J cents a 
pound. Although these cattle were not to be fattened fop the market 
until the next summer, they were all bought during the fall of 1909, 
as it is practically impossible to get together a bunch of cattle in the 
spring. However, it costs something to feed cattle through the 
winter months, and the farmer who buys them in the fall wdth the 
intention of carrying them until the following summer to fatten for 
the market is interested in knowing what it will cost to get them 
through the winter months. In other words, he desires to know the 
spring cost, which is equal to the fall price plus the cost of getting 
the cattle through the winter months. If it were possible to get them 
through the winter months without cost, or without gain or loss in 
weight, the spring and fall prices would be identical, but this can 
seldom be accomplished. As a rule, the steers must be fed, and they 
commonly gain or lose in weight. These expenses and changes in 
live weight all have a bearing on the spring price. 



80 



FEEDING BEEF CATTLE IN ALABAMA. 



The following table presents the fall price, the cost to get each 
steer through the winter, and the spring price after the winter ex- 
penses and changes in live weight have been taken into consideration: 

Table 11. — Average fall and spring prices of the cattle and cost of winter feeding. 

THE YOUNG STEERS. 
[Dec. 6, 1909, to Mar. 31, 1910, 116 days.] 



Lot. 



4 

5 



Ration. 



I Cottonseed meal. . 
Cottonseed hulls.. 
Cottonseed meal.. 
Cottonseed hulls.. 
Johnson-grass hay 



Fan price 
per hundred- 
weight. 



Cost to feed 

each steer 

through the 

winter. 



S3. 50 
3.50 



18.95 
9.83 



Spring price 

per hundred* 

weight. 



S4.41 
4.00 



THE COliMON CATTLE. 
[Dec. 6, 1909, to Apr. 23, 1910. 139 daj^.] 




In lot 4 it cost $8.95 to feed each steer through the winter months. 
In lot 5, where Johnson-grass hay was used, the expense to feed each 
steer for the same length of time was raised to $9.83. The Johnson- 
grass hay increased the expense. When these winter expenses are 
added to the original cost, and allowance made for the winter gains, 
the steers in the spring cost $4.41 and $4.60 per hundredweight in 
lots 4 and 5, respectively, which brought their average price to $30.79 
for lot 4 and $31.11 for lot 5. 

The steers in lots X and Y were cheaper at the end of the winter 
than they were the previous fall. This was due to the fact that they 
gained a few pounds during the winter months (10 pounds each), 
when no expense was attached to feeding them, as they were grazed 
on the open range. It is, of course, an unusual occurrence for these 
two factors to be combined in this way. These cattle were bought in 
the fall of 1909 for $2.26 a hundredweight, but when spring arrived, 
April 23, 1910, their cost per hundredweight was reduced to $2.21. 

FATTENING THE CATTLE ON PASTURE. 

At the close of the winter tests the steers were redivided into lots, 
turned into the summer pastures, and fattened for the late sunmier 
market. 

The winter feeding in lots 4 and 5 was discontinued March 31, 1910. 
On April 2, 1910, the pastures were ready for grazing, so the summer 
fattening tests were inaugurated on this date. The steers in lots 4 
and 5 were combined into one lot and grazed upon the same pasture 
throughout the summer experiment. 



SUMMBB FATTENING ON PASTURE. 



31 



The range or common cattle (lots X and Y) were divided into two 
lots, as nearly equal as possible in quality, size, and breeding, and 
placed upon separate pastures on April 23, 1910. Lot X was fed 
cottonseed cake along with the pasture; lot Y was fed nothing except 
pasture. 

The feeding was done once a day in open feed troughs; these 
troughs were conveniently located in the pastures. In order that all 
of the cattle would come out to the troughs the feeding was done in 
the cool of the evening or about simdown. 

An abundance of water and salt was kept before the animals all 
the time. 

DAILY RATIONS. 

To avoid scouring and other ill results, steers which are being 
fattened must become accustomed gradually to cottonseed meal and 
cottonseed cake. Many feeders increase the feed too rapidly for best 
results. The temptation is to get the steers on full feed within a few 
days after the feeding begins, but this tendency should be curbed. 
The following table illustrates the amount of cottonseed cake given 
each steer. daily by periods of 28 days: 

Table 12. — Daily ration for each iteer during summer fattening. 



Period. 



First 28 davs. . . 
Second 38 days. 
Third 28 days.. 
Foorth 28 days. 
Fifth 28 days... 
Last 7 days 



Cottonaeed cake and {na- 
ture. 



Young Bteen, 

lots 4 and 6 

combined 

(Apr. 2 to 

Aug. 26, 1910, 

147 days). 



Pounds. 
2.19 
4.36 
6.60 
6.00 
6.00 
6.14 



Common 
steers, lota X 
and Yi (Apr. 
28 to Sept 2, 

1910, m 
days). 



Pounds. 

2.84 
3.48 
3.48 
6.00 
S4.01 



1 Pasture cnly. 



* Last 21 days. 



Attention is again called to the fact that the results secured in 
lots 4 and 5 (now combined into one lot) can not be compared with 
those secured in lots X and Y. It should be noted that these lots 
were not started on feeds at the same date, sold at the same time, or 
fed and cared for similarly the preceding winter. Tbjis is not a test 
in which common cattle are compared with good ones. Lots X and 
Y, however, are comparable with each other. 

All of the cattle, except lot Y, which were on pasture alone, were 
given a very small daily feed of cake during the first few weeks. 
Each of the young steers received an average of only 2.19 pounds of 
cake daily durii^ the first 28 days. This amount was increased from 



32 



FEEDING BEEF CATTLE IN ALABAMA. 



time to time, as shown in the table. For a time each steer was eatii^ 
6 pounds of cake a day, but this amount was finally reduced some- 
what on account of scouring and hot weather. 

At first the common steers (lot X) were also given a yeiy small 
allowance of cottonseed cake, each steer receiving an average of 2.84 
pounds of cake daily during the first 28 days. The steers in this lot 
were never given a daily feed of over 6 pounds of cake. The steers 
in lot Y received no feed at all in addition to the pasture, the object 
being to learn whether it would pay to feed cottonseed cake to steers 
of this grade while grazing a fairly good pasture. 



WEIGHTS AND GAINS ON PASTURE. 

The following table shows the average initial weight, average final 
weight, and the total gains and average daily gains of each steer. 
All of the gains were unsatisfactory. To have been entirely satisfac- 
tory the average daily gains should have been not less than 2 pounds. 
The authors are unable to state positively why the gains were no 
greater, but it was probably due to the unusual amount of rain during 
the grazing season. The pastures were on low grounds which con- 
tinued extremely wet throughout the greater part of the test. The 
grass made a good growth and the steers seemed to be well filled 
practically all of the time, but of course the grass that they obtained 
was very soft and full of water. 

Table 13. — WeigJU^, total gains ^ and average daily gains of the steers dvring the summer 

of 1910. 

THE YOUNG STEERS. 
[Apr. 2 to Aug. 26, 1910, 147 days.] 



Lot. 

« 


Number 

of 
steers. 


4 

5 


} « 



Ration. 



Pa»ture and cottonseed cake. 



Average 

initial 

weight of 

each steer. 



Pounds. 

087 



Average 

final 

weight of 

each steer. 



Pounds. 
855 



Average 

total gain 

of each 

steer. 



Pound*. 
168 



Average 

daily gain 

of each 

steer. 



Pounds. 
1.14 



THE COMMON STEERS. 
[Apr. 23 to Sept. 2, 1910, 133 days.] 


X 


28 
15 


PfMliirA find flnt.t/nMM»d caIta. . . , 


572 
580 


761 
757 


189 

177 


1.42 


Y 


Pasture alone 


1.33 









Each of the young steers made a total gain of 168 pounds during 
the 147 days that they were on feed. This was an average daily gain 
of 1.14 pounds. As stated before, these gains were exceedingly 
unsatisfactory. With the amount of cottonseed cake they received 
along with the pasture it was expected that they would make not less 
than an average daily gain of 2 pounds a day. In some fanner feeding 



SUMMEB FATTENING ON PASTUBE. 



88 



work ^ the daily gains secured averaged more than 2 pounds when 
the pastures were supplemented by cottonseed cake. 

The common cattle of lot Y (pasture alone) made fairly satisfactory 
gains, although larger gains were expected. Each steer made an 
average daily gain of 1.33 pounds, or a total gain of 177 pounds for 
the whole summer of 133 days. The steers (lot X) which received 
some cottonseed cake along with the pasture made a very little lai^er 
daily gain than the ones on pasture alone. Each cake-fed steer made 
an average daily gain of 1.43 pounds, or a total gain of 189 pounds for 
the whole summer, while the pasture steers each gained 177 pounds, 
or an average daily gain of 1.33 poimds. 

QUANTITY AND COST OP FEED REQUIRED TO MAKE 100 POUNDS GAIN. 

When cattle are being fattened and the gains are small, they are 
almost certain to be expensive. The results secured in this experi- 
ment were no exception to the general rule. The table following 
shows that the sunmier gains were extremely expensive when com- 
pared with former experiments that have been made in this State. 
At least two factors were involved in making these summer gains 
expensive. First, the cattle were fed a rather heavy ration of high- 
priced cottonseed cake along with the pasture, and, second, the cattle 
did not respond to the liberal feeding, due probably at least in part to 
the wet pastures. 

Table 1^.— Quantity and cost of feed required to make 100 founds of gain, 

THE YOUNG STEERS. 
[Apr. 2 to Aug. 16, 1910, 147 days.] 



Lot. 


Number 

of 
cattle. 


Ratlfln. 


Total cost of 

feed and 

pasture for 

each steer. 


Feed re- 
quired to 
make 100 
pounds of 
gain. 


Cost to make 
100 pounds 

of gain 

(including 

pasture). 


4 


} » 


Pafftnre and cottontwed cake 


$1L54 


423 


$7.06 


5 






THE COMMON CATTLE. 
[Apr. 23 to Sept % 1910, 138 daTs.] 


X 


28 
IS 


Pasture and oottonaeed cake 


19.10 
2.38 


274 
None. 


94.82 


Y 


Pafftnre alone. 


1.55 









It cost $11.54 to feed each steer in lots 4 and 5 through the summer 
when cottonseed cake is valued at $26 a ton and the pasture at 50 
cents a month for each animal. Or it required 423 pounds of cotton- 
seed cake, at a cost of $7.06, to make 100 pounds of increase in live 
weight. This was an unusually expensive gain for summer feeding. 



I See Bureau of Animal Industry Bulletin 131, p. 40. 



34 FEEDING BEEP CATTLE IN ALABAMA. 

The following extract is taken from Bureau of Animal Industry 
Bulletin 131, page 41, which is a report of some previous work done 
in fattening cattle in the summer time on pasture: 

In every case above the cost to make 100 pounds increase in live weight was very 
low. (In one case $1.18 when pasture was used alone, in another case $1.03; when 
cottonseed cake was used it cost only $2.56 to make 100 pounds of gain in one experi- 
ment, and $3.21 in a second test.) When steers are fattened during the winter time 
each pound of gain is put on at a loss, as each pound put on may be expected to cost 
from 8 to 12 cents; and the profit is dependent upon the enhancement of the value 
of the steer over and above the selling value of pounds of gain made. In these tests 
each pound put on during the ^ttening period was put on at a profit, a very unusual 
occurrence in ibttening beef cattle. These cheap finishing gains made the feeding 
operations comparatively safe as far as profits were concerned. As stated before, 
these cheap gains were due to two factors; first, the cattle had a cheap and succulent 
roughage — ^pasture. Second, the amount of concentrated feeds used was kept down 
to a comparatively small figure; from 2.76 to 3.31 pounds of cottonseed cake and 4.48 
poimds of cotton seed were fed each steer daily. 

In lot X, one of the lots of common cattle, 274 pounds of cake 
were required to make 100 pounds of gain, at an expense of $4.82 
per hundredweight. To feed each steer in this lot all summer it 
cost $9.10, when the feeds are valued as above. The cattle in lot Y 
received no cake in addition to the pasture, so it cost only $2.38 to 
feed each one from April 23 to September 2, when pasture is valued 
at 50 cents a month per head. 

FINANCIAL STATEMENT OF THE SUMMEB FEEDING. 

As stated before, the cattle in lots 4 and 5 cost 3^ cents a pound in 
the fall of 1909. These cattle were fed through the winter of 1909-10 
on a light ration of feeds as heretofore outlined. When spring 
arrived, and the expense of the winter feeding had been added to 
fall price, the steers had cost $4.41 and $4.60 per hundredweight 
respectively. These were the values placed upon them at the 
beginning of the summer feeding, April 2, 1910. On August 26, 
1910, they were sold for $4.50 per hundredweight on the farm, after 
a 3 per cent shrink. 

The common cattle in lots X and Y were also purchased in the fall 
of 1909, costing, however, only 2i cents a pound. They ate no 
expensive feeds during the winter months as they were turned out 
on the open range. On April 23, 1910, they were taken off this 
winter range and weighed again, and it was learned that each steer 
had gained 10 pounds during the winter. Owing to the fact that 
they had been fed no feeds during the winter upon which a price 
was placed (open range has no value placed upon it), they were 
really cheaper in the spring of 1910 than they were the previous fall, 
as they had gained in weight. This condition of affairs is, of course, 
very unusual. "When this increase in weight was taken into con- 



6UMMEB FATTENING ON PASTUBE, 8S 

sideration, the cattle cost $2.21 per hundredweight in the spring of 
1910; at the beginning of the summer work this value was placed 
upon them. On September 2, 1910, they were sold and shipped to 
the Atlanta market, realizing $3.87^ per hundredweight for lot X^ 
and $3.60 per hundredweight for lot Y. 

Financial statement of lots 4 and 5. 

Lot 4. Cottonseed cake and pasture: 

By sale 18 steers, 15,064 pounds, at |4.50 per hundredweight |677. 881 

To 18 steers, 12,566 pounds, at $4.41 per hundredweight.'. |554. 16 

To 12,770 pounds cottonseed cake, at $26 per ton 166. 01 

To pafture for 5} months, at 50 cents a month per head 47. 25 

Total expense 767. 42 



9- 



Total loss 89.54 

Loss per steer 4. 97 

Lot 5. Cottonseed cake and pasture: 

By sale 17 steers, 13,978 pounds, at $4.50 per hundredweight 629. 01 

To 17 steers, 11,494 pounds, at $4.60 per hundredweight $528. 72 

To 12,061 pounds cottonseed cake, at $26 a ton 156. 79 

To pasture for 5} months, at 60 cents a month per head 44. 62 

730. 13 

■ ■ ■ ■ ^ 

Total loss 101.12 

Loss per steer 5. 95 

It is seen that the steers in both of these lots were fed at a loss, 
each steer losing $4.97 and $5.95 in lots 4 and 5, respectively. It 
should be noted that the expense of feeding these cattle through the 
previous winter is also charged against them in the above statements. 
The steers in lot 4 were fed through the previous winter on cotton- 
seed meal and hulls, while those of lot 5 had some Johnson-grass hay 
added to the basal ration of cottonseed meal and hulls. More money 
was lost on the steers in lot 5 because of the fact that Johnson-grasa 
hay increased the expense of the winter ration. (See p. 16.) 

This work clearly shows that profits can not be made upon cattle 
when the conditions are as they were in this test. It is true that the 
beef cattle market was demoralized just at the time of sale, but 
even with a normal market it would have been impossible to have 
made money on these young steers. To have come out even on the 
operation the steers of lots 4 and 5 would have had to sell for $5.09 
and $5.24 per hundredweight, respectively. This they would not 
have done even under normal market conditions. Too much high- 
priced feed had been fed to these steers. Furthermore, subsequent 
work seems to teach that, while they were fed too long a time in the 
summer, they were not fed liberally enough during the winter. If 
they had been sold earlier in the summer the financial outcome 
would not have been so discouraging, as the price would have been, 



86 FEEDIKO BEEF CATTLE IN ALABAMA, 

better and considerable high-priced feed would have been saved. 
In fact, a little profit would have been secured if they had been sold 
about July 1. Then again, the expense of feeding them during the 
winter was heavy, while only small gains were secured. It cost $8.95 
and $9.83 to feed each steer in lots 4 and 5 through the winter months. 
If profits are to be made in handling cattle in this manner, the winter 
feed bill must be carefully looked after. 

Two or three methods of feeding can be adopted by which the 
winter feeding can.be done more economically than was the case in 
these tests. In the first place, these young steers were not fed a 
sufficient amount of feed during the winter months. Their ration 
was too nearly a mere maintenance ration. In the second place, 
the open range in some parts of the State can be used to supplement 
the high-priced feeds. With young animals the range can never 
entirely take the place of high-priced feeds, as young animals must 
be fed during the winter months if satisfactory results are secured. 
This system of wintering cattle, however, will disappear as soon as 
the State becomes more densely populated and the large farms are 
divided into small ones. In the third place, the old cotton and com 
fields can be made to be exceedingly profitable when fenced; both 
the young and old animals can be turned on these fields and often- 
times secure one-half of their winter feed from them. This third 
method is a permanent one and will be introduced more and more 
as our farming conditions change. 

Financial statement of lots X and Y. 

tx)t X. Cottonseed cake and pasture: 

By sale 28 steers, 20,665 pounds, at $3.87) per hundredweight $800. 77 

To 28 steers, 16,011 pounds, at $2. 19 per hundredweight $350. 64 

To 14,493 pounds cottonseed cake, at $26 a ton 188.41 

To pasture, 4} months, at 50 cents a month per head. J 66. 50 

605.55 

Total profit 195.22 

Profit per steer 6. 97 

Lot Y. Pasture alone: 

By sale 15 steers, 11,008 pounds, at 13.60 per hundredweight 396. 29 

To 15 steers, 8,697 pounds, at $2.25 per hundredweight 1195.68 

To pasture, 4) months, at 50 cents a month per head 35. 63 

23L31 

Total profit 164.98 

Profit per steer IL 00 

It may be noted that the spring price of these cattle is stated in 
other places to be S2.21 per hundredweight. This is correct for the 
entire lot, but after they were divided it was found that the value of 
lot X was $2.19 and lot Y $2.25 per hundredweight. 

These steers were sold on the farm with a 3 per cent shrink. Those 
in lot X sold for $3.87^ per hundredweight and those in lot Y for 



ST7MMEB FATTENING ON PASTURE. 



87 



$3.60. Exceedingly satisfactory profits were made on these cattle, 
$6.97 clear profit being made on each steer in lot X, while each 
animid in lot Y returned a profit of $11. 

In this particular experiment it did not pay to supplement the 
pasture with the cottonseed cake; more money would have been 
made if the cake had not been used. These results, however, do not 
agree with others secured in former work.* The cattle in lot X did 
not respond to the extra feed of cottonseed cake; this is shown to be 
true by the daily gains. The steers in lot Y, where no cake was fed, 
made an average daily gain of 1.33 pounds, while the steers of lot X, 
where the cake was fed along with the pasture, made an average daily 
gain of only 1.42 pounds. This is unusual and the authors regard 
the results as abnormal. 

SLAUGHTER RECORDS. 

The steers of lots 4 and 5 were shipped to Atlanta, where complete 
slaughter records were secured. Those of lots X and Y were also 
shipped to Atlanta, but no slaughter data were secured. 







Table 16. — Shipping/ weights and slaughter data. 




Lot. 


Number of 
steers. 


Total weight 
on farm. 


Total weight 
at Atlanta. 


Shrhikage 
en route 
per steer. 


Total 

dressed 

weight at 

Atlanta. 


Percent 

dressed out 

by farm 

weight. 


Percent 
dressed out 
by Atlanta 

weight. 


4 

6 


18 
17 


Poundt. 
15,530 
14,402 


Pound*. 
14,920 
13,740 


Pounds. 
33.9 
38.9 


Pounds. 

8,252 
7,531 


53.1 
52.3 


55.3 
54.8 



The cattle were driven 4 miles from the farm to the railroad. 
The shrinkage en route was comparatively small, being 33.9 pounds 
and 38.9 pounds for each animal in lots 4 and 5, respectively. By 
Atlanta weights the steers in lot 4 dressed 56.3 per cent, while those 
in lot 5 dressed 54.8 per cent. 

SUMMARY. 

1. Two separate tests ar6 reported in Part II. The steers in lota 
4 and 5 were a high-grade bunch of young cattle; those in lots X and 
Y were the coromon cattle of Sumter and neighboring counties. 
These tests are not comparable. 

2. The steers in lots 4 and 5 were carried through the winter of 
1909-10 on the following feeds: 

Lot 4: Cottonseed meal, cottonseed hulls. Lot 5: Cottonseed 
meal, cottonseed hulls, Johnson-grass hay. 

The general plan was to give sufficient feed to produce small gains 
throughout the winter months. No effort was made to fatten the 
steers, as they were to be fattened the following sunmier on pasture, 

1 See Boreau of Animal Lidustry Bulletin 131. 



B8 FSBDIKQ BEEF CATTLE IN ALABAMA. 

3. The steers in lots X and Y were carried through the winter of 
1909-10 on the range alone; no purchased feeds were used. The 
object was to fatten these cattle the following summer on pasture. 

4. The steers in lots 4 and 5 ate the following amounts of feed each 
day during the winter: 

Lot 4: Cottonseed meal, 2.35 pounds; cottonseed hulls, 13.29 
pounds. Lot 5: Cottonseed meal, 2.35 pounds: cottonseed hulls, 
6.82 pounds; Johnson-grass hay, 5.50 pounds. 

5. The test was inaugurated December 6, 1909. On this date the 
steers in lots 4 and 5 averaged 624 and 608 pounds in weight. At 
the close of the winter period. April 1, 1910, the steers had attained 
an average weight of 698 and 676 pounds in the respective lots. 

6. The steers in lots X and Y (combined during the winter months) 
averaged 565 pounds in weight at the beginning of the test, December 
6, 1909. At the close of the winter, April 23, 1910, they had attained 
«n average weight of 575 pounds. 

7. To feed each steer through the winter cost $8.95 and $9.83 in 
lots 4 and 5, respectively. Johnson-grass hay increased the expense; 
it did not pay to use the hay along with the cottonseed meal and hulls. 

8. The steers in lots 4 and 5 cost 3i cents a poimd when they were 
purchased in the fall of 1909. At the end of the winter feeding they 
had cost $4.41 and $4.60 per hundredweight, respectively, after the 
gains were taken into consideration. 

9. Owing to the fact that the common cattle in lots X and Y were 
fed nothing except range during the cold months, but at the same 
time gained a little in weight, they were cheaper when spring opened 
than they were the previous fall. They were bought in the fall of 
1909 for $2.25 per hundredweight, and at the end of the winter 
period, April 23, 1910, their cost per hundredweight was reduced to 

10. When the spring of 1910 arrived all the cattle were turned on 
pasture and fattened for the late sununer market. Lots 4 and 5 
were combined into one lot, while lots X and Y were separated into 
two lots. The steers in lots 4 and 5 were fed cottonseed cake along 
with pasture from April 2, 1910, to August 26, 1910. The steers in 
lots X and Y were given the following feeds from April 23, 1910, to 
September 2, 1910: Lot X, pasture and cottonseed cake; lot Y, 
pasture alone. 

11. The steers in lots 4 and 5 (now combined) made an average 
daily gain of only 1.14 pounds diuing the pasture season. This was 
unsatisfactory. 

12. The steers in lots X and Y made an average daily gain of 1.42 
and 1.33 pounds, respectively, during the pasture season. This was 
also unsatisfactory. 



SUMMEB FATTENING ON PASTUBE. 89 

13. Including the cost of pasture, it cost $7.06 to make 100 pounds 
of gain in lots 4 and 5 during the pasture period. These were unusu- 
ally expensive gains for the summer season. 

14. Including the cost of pasture, it cost S4.82 and $1.55 to make 
100 pounds of gain in lots X and Y, respectively. 

15. The reader's attention is called to the fact that the results 
secured with lots 4 and 5 are not comparable with those secured 
with lots X and Y. 

16. Money was lost on the cattle in lots 4 and 5 — ^$4.97 on each 
steer in lot 4, and $5.95 on each one in lot 5. 

17. Excellent profits were realized on the cattle in lots X and Y — 
$6.97 on each steer in lot X, and $11 on each one in lot Y. 

In this experiment it did not pay to supplement the pasture with 
the cottonseed cake. This result, however, does not agree with other 
results secured in former experiments. For reasons stated in the 
text of this buUetin, the authors regard the results as abnormal. 



m. THE VALUE OP SHELTER FOR PATTEWIIf G CATTLE IN 

ALABAMA. 



INTRODUCTION. 

During the winters of 1904, 1905, and 1906 this bureau, working 
in cooperation with the Alabama Experiment Station, carried through 
some tests to determine the value, if any, of shelter in fattening 
southern steers. These results were published in Bulletin 103 of the 
Bureau of Animal Industry. In comparing the daily gains the 
authors stated: 

The animals in pen 2 were fed under an open shed, and pen 6 had no shelter. The 
average daily gains for the three years was 1.55 pounds for the pen under shelter and 
1.47 pounds for the lot without shelter. In the two wet winters (1904-1905 and 1905- 
1906) the largest daily gains were made by the lot under shelter; but in the mild and 
rather dry weather of 1906-1907 the lot without shelter made more rapid gains. 

With regard to feed requirements the authors further stated : 

In two experiments out of three and in the average for three yeais, shelter resulted 
in a slight economy in use of concentrated feeds and a slight loss in the use of roughage. 
In other words, shelter, on the whole, saved 0.2 of a pound of cottonseed meal per 
pound gain and lost 0.49 of a pound of roughage. The steers out of doors consumed 
a larger ration of roughage. 

Or, in other words, when the cottonseed meal is valued at $26 a 
ton and hulls at $7 a ton the shelter saved practically 9 cents on every 
100 pounds of gain made. Sheds can not be built and maintained 
with this small saving. 

However, the above steers were not managed^ with reference to 
bedding and available space for exercise, as they are usually fed on 
the farms of Alabama. 

The feed lots were 16 by 90 feet, the groimd sloping away from the shed. These 
lots had a good slope, but still became very muddy in wet weather. The lot without 
shelter was at times several inches deep in mud, so that the steers had no dry place 
to lie down. None of the lots were bedded, though the sheds were. The feed troughs 
were under the sheds. The water troughs were near the feed troughs and under the 
shed, the water being supplied from a well. The troughs had float valves, so that a 
fresh supply of water was kept in them at all times. 

The average feeder of the State does not confine the fattening 
steers in small lots 16 by 90 feet; the Bureau and Station authorities^ 
however, on account of the lack of ground, had to do so, and of course 
the steers in the lot without shelter were at a disadvantage on account 

40 



VALUE OP SHELTER FOR FATTENING CATTLE. 41 

of the deep mud. When the fanner feeds without shelter the steers 
can usually find a dry piece of ground on which to lie, as they are not 
confined in small lots. 

In connection with another line of work during the winter of 
1910-11 an opportunity presented itself to cany through another 
experiment along this line upon an extensive scale, and the condi- 
tions sun'Oimding the present test were more nearly in keeping with 
average farm conditions than were those of the former experiments. 

The work was done in cooperation with Mr. E. F. Allison, of Sumter 
County, Ala. Mr. Allison furnished the cattle and the feed, and the 
Bureau of Animal Industry and the Alabama Experiment Station 
provided a trained man to look after the details of feeding. Mr. 
L. W. Shook was stationed on the farm and had personal supervision 
of the experiment. 

PLAN OF THE EXPERIMENT. 

This work was planned with two objects in view: 

1. To study various methods of making and saving manure when 
beef cattle are fattened during the winter months. 

One lot of steers was fed on a 5-acre tract of level sandy land, so 
that all the manure they made was deposited upon the land without 
the expense of hauling. A second bimch of cattle was fed in a small 
lot, across one side of which was a good shed. Both the lot and the 
shed were bedded when necessary. The steers could always find dry 
places upon which to lie. An accurate account was kept of the 
amount of bedding hauled; the labor required to haul it, and the ex- 
pense of hauling the manure from the bam to a second 5-acre tract 
of land adjoining the first tract. The comparative value of the two 
methods of making and saving manure is to be finally measured in 
terms of subsequent yields of com and cotton. 

2. To study the value, if any, of shelter in fattening southern beef 
animals. 

The results of the second object are reported in the following pages. 
Sufficient information relative to the first object has not been col- 
lected to warrant a report. 

THE CATTLE. 

The cattle used in this test were a mixed lot of steers, heifers, and 
cows, averaging from 2 to 4 years of age. As the main object of the 
test was to study methods of making and saving manure, the quaUty 
of the animals was somewhat neglected. They were the common 
cattle of Sumter and neighboring counties; only a very few showed 
signs of improved beef blood. They cost $2.30 per hundredweight 
during the late fall of 1910. The price paid shows that the quahty 
was poor, as the best feeders of the county were selUng for $3 to $3.50 
per hundredweight. 



42 FEEDING BEEF CATTLE IN ALABAMA. 

PRELIMINARY MANAGEMENT AND FEEDING. 

A few of the cattle were raised upon the farm where the experiment 
was conducted; the majority, however, were purchased from neigh- 
bors. Some of the cattle were purchased early in the fall; these, 
together with the few that were raised on the farm, were grazed upon 
a large pasture, with no additional feed, from October 10 to October 21 , 
1910. On October 21, 30 head were taken from this pasture and 
turned into a peanut pasture where hogs and sheep were grazing. 
While they were on peanuts each animal was given a daily feed of 1 
pound of cottonseed cake. On October 31 they were taken back to 
the first-mentioned pasture and the daily allowance of cake was 
raised to 2 pounds for each animal. As cold weather approached the 
value of the pasture gradually decreased, and the amount of cake was 
therefore gradually increased. By December 16, 1910, each animal 
was eating practically 4 pounds of cake each day. On this date they 
were taken off the pasture, as it was of no further value, and the test 
inaugurated. 

The cattle were all dehorned before the experiment began. 

Individual weights of the cattle were secured at the beginning and 
end of the test. Lot weights were secured every 28 days. 

Feeding was done twice each day, once about 7 o'clock in the morn- 
ing and again at 4 o'clock in the afternoon. The cottonseed jneal was 
mixed with the hulls by hand. Water was kept before the cattle all 
the time. Salt was fed once a week. 

LOTS AND SHELTER. 

The cattle were divided into two lots. Lot 1 was fed in a small lot, 
across the east side of wliich extended a shed and the feed troughs; 
the animals therefore had the privilege of standing either under the 
shed or in the open lot. From time to time sufficient bedding was 
hauled to cover the entire lot. The object was to keep the whole 
lot well bedded, but several times during the test that part of the 
lot not under shelter became exceedingly muddy. However, the 
cattle could always find dry places. 

The steers in lot 2 were fed on a 5-acre tract of sandy land with no 
shelter at all. This tract of land had been under cultivation for 
several years, so the trees had been removed. The feed troughs, 
which were also in the open, were made in such a way that they could 
be pulled from place to place; in this way the manure was evenly 
distributed over the field. The soil was sandy, so the ground never 
became exceedingly muddy, although the winter of 1910-11 was an 
unusually wet one. 



VALUE OF SHELTER FOB FATTENING CATTLE. 43 

CHARACTER AND PRICE OF FEEDS. 

Cottonseed meal and cottonseed hulls were fed to both lots. No 
other feeds were used. Both the meal and hulls were of good quality. 
The following prices were taken as a basis upon which to make the 
financial estimates : 

Per ton. 

Gottonaeed meal ■. $26.00 

Cottonaeed hulla 7. 00 

DAILY RATIONS. 

There seems* to be no doubt that the majority of our southern 
farmers feed too much cottonseed meal to cattle which are being fat- 
tened. The average feeder is tempted to increase the amount of cot- 
tonseed meal too rapidly at the beginning of the feeding period and 
continue to increase the amount until the total feed of meal is 
entirely too great. When this is done the cattle are oftentimes 
"burnt out" by the time they have been fed from 70 to 80 days 
and must then be sold often under unfavorable market conditions. 
"Burnt out" cattle can not be held for better market conditions. 

The table below shows the average daily ration of cottonseed meal 
and hulls in this experiment by periods of 28 days each: 

Tablb 17. — Average quantity of feed eaten by each animal daily. 
[Deo. 16, 1910, to Mar. 28, 1911, 103 days.] 



Period. 


Lot 1 (shelter). 


Lot 2 (no shelter). 


First 28 days 


/ 4.15 pounds cottonseed meal 


4.19 pounds cottonseed meal. 


Second 28 da3rs 


1 18.11 pounds cottonseed hulls 

J 6.04 pounds cottonseed meal 


16.63 pounds cottonseed hulls. 
6.05 pounds cottonseed meal. 


Third 28 days 


\20.17 pounds cottonaeed hulls 

/ 6.33 pounds cottonseed meal 


20.12 pounds cottonseed hulls. 
6.20 pounds cottonseed meal. 


Last 19 days 


U9.39 pounds cottonseed hulls 

/ 6.19 pounds cottonseed meal 


19.61 pounds cottonseed hulls. 

6.18 pounds cottonseed meal. 

18.69 i>ounds cottonseed hulls. 




\18.61 pounds cottonseed hulls 



At the beginning of the test the cattle averaged 578 and 585 
pounds in weight in lots 1 and 2, respectively. 

These cattle were, in a way, accustomed to cottonseed meal, as 
they had received a small feed of cottonseed cake for several weeks 
previous to the beginning of the experiment, yet their daily allow- 
ance of meal was below 3 pounds an animal for several days after 
the test begun. This amount was gradually raised and each steer 
ate an average of 4.15 pounds of cottonseed meal daily during the 
first 28 days; along with this amount of meal an average of 18.11 
pounds of hulls were consumed daily by each animal. They were 
given all of the hulls they would clean up. The cattle in lot 2 ate 
practically the same as those in lot 1. The heaviest feeding of cot- 
tonseed meal occurred in lot 1 during the third period, when an 
average of 5.33 pounds of cottonseed meal was given each animal 
daily. 



44 



FEEDINQ BEEF CATTL£ IN ALABAMA. 



The feeding continued for 103 days, yet no ill results, such as dizzi- 
ness, staggering, or blindness, followed the use of the cottonseed 
meal. As before stated, many feeders, on accoimt of the excessive 
use of cottonseed meal, are not able to feed for more than 80 days. 

WEIGHTS AND GAINS. 

Although the daily allowance of cottonseed meal was maintained 
at a rather small amount, the cattle made satisfactory gains. At 
the same time no losses were sustained as a result of feeding meal 
too liberally. 

Table 18. — Weights and gains. 
[Dec. 16, 1910, to Mar. 28, 1911.] 



Lot. 


Number 

of 
cattle. 


Ration. 


initial 

weight 

Doc. 10, 

1910. 


Final 
weight 
Mar. 26, 

1911. 


Total 
gain of 

each 
animal. 


ATorage 
daily 

gain of 
each 

animal. 


1 (shelter) 

2 (no shelter) 


33 
34 


Gottonaoed meal and oottonaeed 

hulls. 
do 


Pounds. 
578 

685 


Pounds. 
754 

757 


Pounds. 
176 

172 


Pounds. 
1.71 

1.67 







Each animal in lot 1, fed under shelter, weighed on an average 578 
pounds at the beginning and 754 pounds at the close of the test, 
making a total gain of 176 pounds, or an average daily gain of 1.71 
pounds. It is seen that the cattle which had no shelt'^.r (lot 2) also 
made good gains, as each one made a total gain of 172 pounds during 
the test, or an average daily gain of 1 .67 pounds. As far as gains were 
concerned, the shelter was of no practical value, as the cattle with 
shelter made an average total gain of only 4 pounds more than the 
ones without shelter. 

QUANTITY AND COST OF FEED REQUIRED TO MAKE zoo POUNDS 

GAIN. 

Many feeders believe that a fattening animal will increase in weight 
during the winter months very much more economically when he is 
sheltered than when he is forced to remain out in the open weather. 
The foUowing table shows that there are, at least, no striking results 
to be secured from the employment of shelter for fattening animals 
under the conditions of this test: 

Table 19. — Quantity and cost of feed required to make 100 pounds of gain. 

[Dov . IG, 1910. to Mar. 28, 1911.] 



Lot. 



1 (shelter)... 

2 (no shelter) . 



Ration. 



f Cottonseed meal 
I Cottonseed hulls 
[Cottonseed meal 
[Cottonseed hulls 



Feed re- 
quired to 
make 100 
pounds of 
gain. 



Pounds. 

288 
1,120 

292 
1,122 



Cost to make 

lOOpounds 

ofgain. 



17.06 
7.72 



VALUE OF SHELTER FOR FATTENING CATTLE. 45 

When shelter was employed Got I) it required 288 pounds of 
cottonseed meal and 1,120 pounds of hulls, at a cost of $7.66, to make 
100 pounds of gain. When no shelter was provided Got 2) the same 
gains were made with 292 pounds of meal and 1,122 pounds of huUs, 
at a cost of $7.72. In other words, the shelter saved 6 cents on each 
100 pounds of gain made. 

Sheds or bams can not be built and maintained with this small 
saving. Other considerations, however, may make it profitable to 
employ a good shelter for fattening cattle. For instance, when it is 
impossible to save the manure in any other way it is, without doubt, 
a wise thing to build bams or sheds for conserving it. 

PROFITS ON COTTONSEED MEAL AND HULLS AS A RESULT OP 

PEEDING THEM TO THE CATTLE. 

In this test the cottonseed meal and hulls were sold by means of 
the cattle at a handsome profit. Furthermore, the fact must not be 
overlooked that the greater part of the fertilizer value of these feeds 
was left on the farm after they had passed through the cattle. The 
financial statement shows that with lot 1 the total cost of the meal 
and hulls was $444.17, and there remained a clear profit of $227.15 
after paying all expenses. With lot 2 the result was even better, the 
feed in this case costing $451.81 and the net profit being $254.34. 

FINANCIAL STATEMENT. 

This mixed bunch of cattle was bought during the fall of 1910 for 
an average price of $2.30 per hundredweight. When they were ready 
to be shipped they were driven 3 miles to the railroad at Bellamy, 
AJa., and sent to New Orleans, where slaughter data and sale prices 
were secured. It cost 40 cents a hundredweight to ship them to 
New Orleans, when freight, commission, yardage, weighing, labor, and 
feed en route were all taken into consideration. At New Orleans the 
cattle in lot 1 sold for an average price of $5 per hundredweight, while 
those in lot 2 sold for an average price of $5.06 per hundredweight. 

Financial statement. 
Lot 1. Shelter: 

By sale of 33 cattle, 24, 134 pounds, at $5 per hundredweight $1, 206. 70 

To 33 cattle, 19,080 pounds, at $2.30 pdf hundredweight $438. 84 

To 11,677 pounds cottonseed meal, at $26 per ton 216. 80 

To 64,962 pounds cottonseed hulls, at $7 per ton 227. 37 

To shipping expenses, at 40 cents per hundredweight 96. 54 

Total expense 979. 55 

Total profit 227. 15 

Profit per animal 6. 88 



46 



FEEDIKO BEEF CATTLE IN ALABAMA. 



Lot 2. No shelter. 

By sale of 34 cattle, 24,963 pounds, at $5.06 per hundredweight $1, 26a I3i 

To 34 cattle, 19,875 pounds, at |2.30 per hundredweight $457. 13 

To 17,084 pounds cottonseed meal, at |26 per ton 222. 09 

To 65,634 pounds cottonseed hulls, at $7 per ton 229. 72 

To shipping expenses, at 40 cents per hundredweight 99. 85 

Total expense ; 1,008.79 

Total profit 254.34 

Profit per animal 7. 48 

Each animal in lot 1 returned a clear profit of $6.88 above all 
expenses, while each animal in lot 2 returned a profit of $7.48. 
Therefore the animals which had no shelter were finally more profit- 
able than those which were provided with a good bam. This was 
due to the fact that the cattle without shelter sold for a little higher 
price at New Orleans than the others. 

SUMMARY. 

Table 21. — Summary statement. 



Averago cost of cattle in lall 1910, 

per niindredwf>ight. 
Ration for each lot 

Average initial weight of each 

animal. 
Average final weight of each animal. 
Average total gain of each animal. . 
Number of days on feed 

Average daily gain 

Feed to make 100 i>oimds of gain . . . 

Cost to make 100 pounds gain 

Selling price of cattle per hundred- 
weight in New Orleans. 

Entire cost per hundredweight to 
^ip them to New Orleans. 

Total profit on each animal 



Lot 1 (shelter). 



12.30 

Cottonseed meal and cottonseed 

hulls. 
578 pounds 

754 pounds 

176 i)ounds 

Dec. 16, 1910, to Mar. 28, 1911 

(103 days). 

1.71 pounds 

288 pounds meal, 1,120 pounds 

hulls. 

$7.66 

$5.00 

$0.40 

$6.88 



Ix>t 2 (no shelter). 



$2.30. 

Cottonseed meal and cottonseed 

hulls. 
585 pounds. 

757 pounds. 
172 pounds. 
Dec 16» 1910, to Mar. 28, 1911 

(103 days). 
1.67 pounds. 
292 pounds meal, 1,122 pounds 

$7.72. 
$5.06. 

$a40. 

$7.48. 



1. The cattle (67 in number) used in the test were a mixed lot of 
steers, heifers, and cows, averaging from 2 to 4 years of age. As the 
original object of the work (not reported, however, in this publican 
tion) was to study methods of making and saving manure, the quality 
of the animals was somewhat neglected. 

2. The object of the experiment, herein reported, was to study the 
value, if any, of shelter in fattening southern beef animals, 

3. The cattle cost on the average $2.30 per hundredweight. 

4. The test was inaugurated December 16, 1910, and closed March 
28, 1911, a period of 103 days. 

5. The cattle were divided into 2 lots, one without shelter and one 
with shelter. Both lots were fed similar rations of cottonseed meal 
and cottonseed hulls. 

6. At the beginning of the test the average weight of each animal 
in lots 1 and 2 was 678 and 585 pounds, respectively. 



VALUE OF SHELTER FOR FATTENING CATTLE. 47 

7. Each animal in lots 1 and 2 made an average total gain of 176 
and 172 pounds, respectively. 

8. In lot 1, where shelter was employed, it required 288 pounds of 
cottonseed meal and 1,120 pounds of hulls to make 100 pounds of 
gain in live weight, while in lot 2, where no shelter was used, 292 
pounds of meal and 1,122 pounds of hulls were required to make 
the same gains. 

9. It cost $7.66 and S7.72 to make 100 pounds of increase in live 
weight in lots 1 and 2, respectively. 

10. Shelter saved only 6 cents on each 100 pounds of gain made. 

11. A clear profit of $6.88 and $7.48 was made on each animal in 
lots 1 and 2, respectively. 



IV. EARLY COMPARED WITH LATE FATTENING OF STEERS 

ON PASTURE. 



INTRODUCTION. 

The fanner who fattens cattle on pasture is often undecided as to 
the proper time to sell. The cattle may be sold during the early 
summer months, after being fed for 90 days, or they may be carried 
throughout the whole pasture period and sold late in the fall just 
before the pastures are exhausted. The feeder, however, is familiar 
with the fact that fat cattle bring better prices in the early than in 
the late summer months. Few cattle of any kind are oflfered for sale 
during May, June, and the early part of July, so that if fat steers are 
held and not marketed until August and September they come in 
competition with thousands of grass-fat cattle. This large supply of 
grass cattle naturally depresses the price's of all classes. However, 
gains are made cheaply during the pasture season, and notwithstand- 
ing the fact that cheaper prices obtain late in the summer, the feeder 
often can not decide whether it would pay better to rush his animals 
for the early summer market, or feed a small supplementary feed, 
thus making the gains cheaply and slowly, and sell late in the 
sflmmer. 

In order to assist the farmer in dealing with this feeding problem, 
the experimental work hereinafter described was undertaken. When 
steers are bought right, fed correctly, and sold intelligently, it has 
been previously demonstrated that satisfactory profits can be 
realized when they are fattened on pasture.* The present test was 
carried out with the object of studying the problem as to whether it 
is more profitable to begin feeding early in the spring and feed a 
rather heavy ration of cottonseed cake along with the pasture for a 
short time, or to delay the inauguration of the feeding until the 
pasture grasses are well started in the spring and feed a light ration of 
cake along with the pasture for a longer period of time. 

PLAN OF THE WORK. 

The test, extending over three years, was carried on during the 
pasture seasons of 1909, 1910, and 1911. The cattle in each case 
were bought the previous fall, because they could be bought much 

1 See Bureau of Animal Industry Bulletin 131« 
48 



COMPABISON OP EABLY AND LATE FATTENING. 49 

cheaper in the fall than in the spring. In fact, steers in this section 
can hardly be purchased at all during the spring months. As they 
were not to be fattened until the following summer, it was necessary 
to make a study of the cheapest and best methods of getting them 
through the winter months. However, this part of the test is not 
presented here. Some results of wintering steers preparatory to 
summer fattenii^ may be seen in Part II of this bulletin, and in 
Bureau of Animal Industry Bulletin 131. 

When the grass appeared in the spring the winter feeding was dis- 
continued, and the pasture fattening work inaugurated. The feed- 
ing was done on the farm of Messrs. Cobb and McMillan, of Sumter 
County, Ala. They purchased the cattle and the feed, and provided 
the pastures, which were divided into various fields in order to 
facilitate the work. The bureau and the Alabama Elxperiment 
Station provided a trained man to live on the farm and have personal 
supervision of the tests. Mr. W. F. Ward, one of the authors of this 
publication, was stationed on the farm. 

The weight of each steer was secured at the beginning and end of 
each test, and the total weight of each lot was noted every 28 days. 
When the steers were sold some of them had to be driven 9 miles to 
the shipping point at Scooba, Miss., while others were driven 12 
nules to Epes^ Ala., for loading. 

THE CATTLE AND THE PASTURE. 

As far as possible grade Aberdeen-Angus, Shorthorn, Hereford, 
and Red PoUed steers were employed ; a few animals had a pi^domi- 
nance of Jersey and scrub breeding. They were all bought of farmers 
in Sumter, Wilcox, Marengo, and neighboring counties, so they repre- 
sented fairly accurately the average cattle of the western part of 
Alabama. In age they varied from 2 to 4 years. As will be seen 
later, the average weight at the beginning of the test was about 
640 pounds. When compared with northern cattle it is seen that 
they were small, but they were as large as the averj^e of the State. 

The cattle were divided into two lots, one early and one late 
fattening, in each of the three years during which the experiment 
lasted. The early fattening lots had the designation lot F in each 
year, and the late fattening lots were called lot B. There were, 
therefore, three lots F and three lots B. 

The summer pastures used in these experiments consisted of a 
mixture of sweet clover (Melilotus), Japan clover O^spedeza), 
Johnson grass, crab grass, and some Bermuda grass. The sweet 
clover became available for grazing about April 1, while the Japan 
clover afforded practically no grazing until June 15. In some sec- 
tions of the country sweet clover is considered a pest, as stock will 



50 l?BEl)llfG BEEF CATTLE IN ALABAMA. * 

not eat it, but in the South, or at least in Alabama, all kinds of stock 
eat it with great relish; they take to it as readily as to alfalfa. 

The pasture was divided into fields, the size of each one depending 
upon the number of cattle grazed upon it, and also upon whether 
the steers were to be fed a light or a heavy supplementary feed. 
The object was to have an abundance of pasture for each lot of cattle. 
The early fattening lots of cattle (lot F) were turned on the pasture 
at a very early date, in fact before the grasses had become thoroughly 
established. The exact dates will be given later on. 

The cattle were fed but once a day. This was done about sundown, 
so that they would all come out to the troughs, which were placed 
at convenient places in the pastures. No feed was thrown upon 
the ground. 

No shelter, except trees, was provided, but the cattle did not suflFer 
from the heat, as the pastures contained plenty of good shade trees. 
When a summer shade is provided cattle will suffer no more from 
heat in Alabama than they will in Illinois or Iowa. 

While there were ticks in the pasture the cattle were not permitted 
to become badly infested with them; a dipping vat was used to keep 
down heavy infestation. In the three years' work, during which 
time 224 head of cattle were fattened, only one or two cases of Texas 
fever developed, and none of these was lost. In future work it is 
expected that the tick will be entirely eliminated. 

QUALITY AND PRICE OF FEEDS. 

The cottonseed cake was purchased upon the market, so an average 
market price was taken in making up the financial statements. 
It must be borne in mind, however, that prices vary from time to 
time and from place to place. For instance, cottonseed cake is 
valued at $26 a ton in this publication, but at the present writing 
(Dec. 20, 1911) cake can be purchased for $21 a ton. The price 
mentioned above, $26 a ton, very closely approximates the avera^ 
price for the years 1909, 1910, and 1911. The pasture is valued at 
50 cents per month per steer. 

The cottonseed cake had been broken into nut size and sacked. 
This was done by the mill. The cake can be purchased in the lai^ 
cake size, just as it comes from the press, for about $2 a ton less than 
the nut size. Some feeders find that it pays to break the cake on 
their own farms. As a whole, the cake was of excellent quality. 
Poor and damaged cake was fed a few times, when the good mate- 
rial could not be secured. 

DAILY RATIONS. 

The steers in lot B each year were fed longer than those in lot F, 
the object being to start lot F on feed a few weeks before lot B, and 
also to give the animals a heavier supplementary ration of cotton- 



GOMPABISON OP EABLY AND LATE PATTENIKG. 



61 



seed cake. This plan was followed out except in 1911. The spring 
of that year was an unusually dry one, and as a result the pastures 
were not ready for grazing as early as usual, consequently the lots 
were started on feed the same date but sold at different times. The 
steers in lot B were started on feed April 9 in 1909, April 7 in 1910, 
and April 21 in 1911. Those in lot F were started on feed March 
19 in 1909, March 25 in 1910, and April 21 in 1911. The cattle in the 
B lot were sold August 26 in 1909, August 2 in 1910, and September 
8 in 1911. Those in the F lot were sold August 5 in 1909, June 23 in 
1910, and August 27 in 1911. Thus the steers in the B lot were fed 
an average of 137J days, while those in the F lot were fed an average 
of 119} days. 

The pastures upon which the two lots of cattle grazed were not 
exactly similar throughout the whole test, as those in the F lot were 
started at an earlier date (except in 1911) than those in the B lot. 
As a matter of fact, the pastures in the case of the F lot were of very 
small value during the fh'st two or three weeks of the tests ; however, 
the experiment was outlined to learn whether it is profitable to start 
steers on feed during the very early spring months. On account of 
the fact that the pastures were short at this early date the cattle of 
the F lot were started on a rather heavy feed of cottonseed cake. 

Table 22. — Daily feed of cottonseed cake by period-, of 28 days. 





liOt B (long feedtaig). 


Lot F (short feeolng). 


Period. 


Apr. 9 to 


Apr. 7 to 

Aug. 2, 

1910. 


Apr. 21 to 

Sept. 8, 

1911. 


Mar. 19 to 

Aug. 5, 

1909. 


Mar. 25 to 

June 23, 

1910. 


Apr. 21 to 

Aug. 27, 

1911. 


First 28 days 


Pounds. 
2.35 
3.33 
3.54 
3.67 
3.83 
M.OO 


Pounds. 
2.21 
4.41 
3.80 
3.66 
«3.50 


Pounds. 
2.88 
3.76 
3.72 
3.76 
•3.76 


Pounds. 
3.24 
3.91 
4.82 
5.00 
6.00 


Pounds. 

3.27 

4.57 

5.00 

1 5. 00 


Pounds. 
3.40 


Second 28 dairs 


4.87 


Third 28 days 


4.97 


Fourth 28 days 


6.00 


Fifth 28 days 


45.00 


Sixth 28 days 



















1 For 7 days. 
> For 6 days. 



> For 29 days. 
« For 17 days. 



ft For 14 days. 



It is seen that the steers in the B lot were given from 2.21 to 2.88 
pounds of cottonseed cake at the inauguration of the tests, while 
those in the F lot ate from 3.24 to 3.40 pounds each daily. At the 
close of the tests each steer in the B lot was consuming from 3.5 
pounds to 4 pounds of cake, while those in the F lot were eating, on 
the average, 5 pounds daily. As a matter of fact there was prac- 
tically no difference in the total quantity of cake fed to each steer 
in lots B and F, the main difference being that the steers in the F lot 
ate their amounts of feed in the fewer number of days. 

While, to many feeders, the daily feed of cottonseed cake seems 
small, still reasonably g(X>d gains were secured when the size of the 



52 



FEEDING BEEF CATTLE IN ALABAMA. 



cattle is considered. The steers in the B lot averaged practically 
600 pounds in weight at the inauguration of the tests, and an averf^e 
daily gain of 1.87 pounds was secured. Those in the F lot were 
somewhat laiger, averaging practically 690 pounds in weight, and an 
average daily gain of 2.04 pounds was obtained. Large amounts of 
cake are not required to obtain good gains when the cattle are grazing 
a reasonably good pasture. It is in any event impracticable to feed 
a heavy ration of cake along with pasture, as scours develop quickly 
when cottonseed cake is fed too freely. Scours occurred in fact in a 
few cases when no more than 5 pounds of cake was fed each steer daily. 
In the North and Northwest, where com is cheap, it is practicable and 
usually profitable to supplement the pasture with a daily ration of 
from 15 to 18 pounds of com daily for each steer, but there is no feed 
in the South cheap enough to be used in such large amounts. 

TOTAL AND DAILY GAINS. 

Table 23 outlines the initial and final weights and the gains of each 
lot, also the average total and daily gains of each steer. 

Table 23. — Weights and gains (summary ofS years). 



Lot 


Num- 
ber of 
steers. 


Days 
fed. 


Year. 


Ration. 


Initial 
weight 
of lot 


Final 
weight 
of lot 


Total 

gain of 

lot. 


Average 
total 

gain of 
each 
steer. 


Average 
daily, 
gain. 


F (short period).. 


35 

30 

I 25 


140 

91 

128 


1909 
1910 
1911 


Pastnre and cake 
do 


Pound*. 
25,321 
20,042 
16,522 


Pounds. 
34,919 
26,062 
22,808 


Pound*. 
0,596 
6,020 
6,286 


Pound*. 
274.2 
200.7 

257.4 


Pounds. 
1.06 
2.21 


do.... 


1.06 








8-year average .... 










2.04 




f 75 

34 

I 25 


154 
119 
140 


1909 
1910 
1911 


Pasture and cake 
..... do. .......... 








. 




B (lonf period)... 


47,916 
19,586 
14,123 


69,664 
27,514 
20,128 


21,748 
7,928 
6,006 


289.9 
233.2 
240.2 


1.88 
1.96 




do 


1.72 








3-year average 










1.87 























These cattle were from 2 to 4 years old, and small for their age. It 
should be remembered, however, that the initial weights were all 
taken at the close of the winter months, when the animals were in 
their lightest form. The steers in the F lot averaged 723, 668, and 
661 pounds in weight at the inauguration of the pasture work in 1909, 
1910, and 1911, respectively, while those in the B lot averaged 639, 
576, and 565 pounds, respectively. The steers in the F lot, the short- 
fed ones, made an average daily gain of 1.96, 2.21, and 1.96 pounds in 
1909, 1910, and 1911, respectively, or an average daily gain of 2.04 
pounds for the three years. The steers in the B lot, the long-fed 
cattle, made an average daily gain of 1.88, 1.96, and 1.72 pounds in 
1909, 1910, and 1911, respectively, or an average of 1.87 pounds for 
the three years. The steers in the F lot were fed a heavier ration of 
cottonseed cake than those in the B lot, and as a result gained more 



GOMPABISON OP EARLY AND LATE FATTENING. 



53 



rapidly. When the size of the cattle is taken into account it is seen 
that the gains were satisfactory. 

At the end of the feeding periods the steers in the F lot had attained 
an average weight of 998, 869, and 885 pounds in 1909, 1910, and 1911, 
respectively, while those in the B lot were somewhat smaller. For 
southern cattle they were of good size — ^larger than the average — 
but the southern markets prefer larger carcasses than these cattle 
produced, and will pay a premium for the large steers. 

QUANTITY AND COST OP FEED REQUIRED TO MAKE zoo POUNDS 

GAIN. 

Table 24 shows the number of pounds of feed required to make 100 
pounds of gain in each case, the cost of the cottonseed cake to make the 
gains, and also the cost to make the increase in live weight when both 
the cake and the pasture are charged against the gains. It is seen 
that the increase in live weight during the fattening period was put 
on at a profit; that is, each pound added to the weight of the steers 
during the fattening period did not cost as much as it could be sold 
for on the market. This is an unusual state of affairs in fattening 
cattle, as under average winter conditions, and summer conditions, 
also, when a heavy supplementary grain feed is given, each pound of 
increase during the fattening period is made at a loss. 

The economical gains in these tests were mainly due to two factors: 
First, the daily gains were satisfactory, notwithstanding the fact that 
only a small amoimt of high-priced feeds was consumed by each steer; 
and, second, the animals were grazing a pasture — the cheapest feed 
that can possibly be obtained in Alabama. When a large amount of 
concentrated feed is used to supplement the pasture the cost of the 
increase in weight will be much more expensive than was the case in 
these experiments. 

Table 24. — Quantity and cost of feed required to make 100 poundi of gain. 



Lot 



F (aihart period). 



B (long period). 



Number 

of 
steers. 



I 



35 
30 
25 



75 
34 
25 



Year. 



1900 
1910 
1911 



1900 
1910 
1911 



Ration. 



Pasture and cake. 
do 

....do ; 



3-year average. 



Pasture and cake. 

....do 

....do 



3-year average. 



Cottonseed 
cake re- 
quired to 
make 100 
pounds ol 
gain. 



Pounds, 
224 
197 
244 



220 



181 
176 
210 



185 



Cost to make 100 
pounds of gain. 



Cake. 



S2.91 
2.56 
3.17 



2.86 



2.35 
2.29 
2.73 



2.41 



Cake and 
pasture. 



$3.76 
3.32 
4.02 



3.00 



3.24 
3.24 
3.70 



3.33 



54 



FEEDING BEEF CATTLE IN ALABAMA. 



In the F lot it is seen that 224, 197, and 244 pounds of cottonseed 
cake were required to make 100 pounds of increase in live weight in 
the years 1909, 1910, and 1911, respectively, or, averaging the three 
years, 220 pounds of cake were eaten for every 100 pounds of gain. 
In the B lot 181, 176, and 210 pounds of cake were fed for every 100 
pounds of gain in live weight in 1909, 1910, and 1911, respectively, 
or an average for the three years of 185 pounds. The saving of cot- 
tonseed cake in favor of the B lot was due to the fact that the steers in 
these lots wore given a smaller daily allowance than those in the 
Flot. 

The total expense in the F lot to make 100 pounds increase in live 
weight when the pasture and cake are both' chained against the gains 
was $3.76, $3.32, and $4.02 in 1909, 1910, and 1911, respectively, or 
an average of $3.69 for the three years. The total cost to make the 
same gains in the B lot was $3.24, $3.24, and $3.70 in 1909, 1910, and 
1911, respectively, or an average of $3.33 for the three years. 

FINANCIAL STATEMENT. 

As will be seen in the table below, the steers were purchased at 
various prices at the beginning of the tests. They cost from $2.95 to 
$3.50 per hundredweight, depending upon the size and quality of the 
steers and the year in which they were purchased. When the steers 
were ready for sale buyers came to the farm and purchased them on 
the farm, allowing for a 3 per cent shrink. In one case Got B, 1909) 
they were sold as low as $3.90 per hundredweight on the farm; in no 
instance did they sell for more than $4.50 per hundredweight. After 
being sold they were shipped to various southern markets. Two or 
three loads were sent to Meridian, Miss., some were sent to Atlanta, 
Ga., while several carloads were shipped to New Orleans. The table 
below shows, among other things, the initial cost of the cattle each 
year, the selling price each year, and the total profit on each animal. 

Table 26. — Financud statement. 



Lot. 


Num- 
ber of 
stoers. 

f 35 
30 
25 

76 
34 
25 


Year. 


Ration. 


Initial 
price 
per 
hun- 
dred- 
weight. 


Initial 

cost of 

each 

steer. 


Cost of 
feed 

eaten 
by each 

steer. 


Total 

cost of 

each 

steer. 


Selling 
price 

hun- 
dred- 
weight. 


mwng 

price 

or each 

steer. 


Pioflt 

on 

each 

steer. 


F (short fed). 


1900 
1910 
1911 

1909 
1910 
1911 


Pasture and cake. 

do •. . 

do 

3-year aver- 
age 

Pasture and cake. 

do 

do 

3-year aver- 
ago 


13.20 
3.20 
3.50 


123.15 
21,38 
23.13 


siass 

6.64 
9.98 


$33.48 
28.02 
33.01 


$4,375 
4.60 
4.50 


$41.73 
37.92 
39.82 


$&26 
0.90 
6.81 




3.28-1- 


22.56 


0.08 


31.63 


4.46+ 


39.98 


8.30 


B (long fed).. 


2.95 
2.95 
3.50 


18.85 
16.99 
19. n 


9.38 
7.33 
8.89 


28.23 
24.32 
28.66 


3.90 
4.60 
4.60 


35.14 
35.32 
35.14 


6.91 

n.oo 

6.48 




3.05-1- 


17.80 


a 91 


27.46 


4.16+ 


36l19 


7.78 



COMPABISON OF BABLY AND LATE FATTENING. 



55 



It is seen that excellent profits were made in all the tests. In 
the F lot clear profits of $8.25, $9.90, and $6.81 were made on each 
steer in 1909, 1910, and 1911, respectively; an average profit of $8.30 
was made on each animal. In the B lot clear profits of $6.91, 
$11, and $6.48 were made in 1909, 1910, and 1911, respectively. In 
these lots an average profit of $7.73 was secured on each steer; or, 
those cattle which were started on feed early, fed a heavy ration of 
cake along with the pasture, and marketed early in the summer 
months, retimied a slightly greater total profit — ^$0.57 each — ^than 
the ones which were started on feed later and finished for the market 
at a late date. This is not a marked difference, however, in favor of 
the early method of feeding. The greatest advantage in favor of 
the early method of fattening cattle during the smnmer months is 
one that does not appear in a test of this kind. When the steers are 
disposed of at an early date the pastures can be grazed by a second 
bunch of cattle, or the grass has an opportunity to make an extra 
growth before cold weather sets in, thus affording extra feed for the 
winter months. With many farmers late pastures are of great value 
in saving winter feeds. 

SUMMARY. 

Table 27. — Summary of averages. 



Average pounds of cottonseed cake eaten by each steer daily in 1909 

Average pounds of cottonseed cake eaten by each steer dally in 1910 

Average pounds of cottonseed cake eaten by each steer daily in 1911 

Average daily gains for three years 

Average number of jpounds of cottonseed cake to make 100 poimds of gain 

Average cost of cottonseed cake to make 100 pounds of gain 

Average total cost to make 100 pounds of gain ( both pasture and cake included) 

Average initial cost of steers per hundredweight 

Average selling price of steers per hundredweight 

Average profit on each steer 



Lots 


Lotr 


(long fed). 


(short fed). 


PowndM. 


Powndi. 


3.40 


4.39 


3.45 


4.33 


3.60 


4.66 


1.87 


2.04 


186 


220 


DoUan. 


DoPars. 


Z41 


2.86 


3.33 


3.69 


3.05+ 


3.28+ 


4.16+ 


4.45+ 


7.73 


&30 



1. The object of this part of the work was to determine whether 
it is more profitable to feed steers a short or a long period of time 
when they are being fattened on pasture. 

2. Grade Aberdeen-Angus, Shorthorn, Hereford, and Red Polled 
steers, with a few commoner ones, were used. They were bought 
in Sumter and neighboring counties and represented fairly accurately 
the average cattle of the western part of Alabama. 

3. The steers were fed on pasture and cottonseed cake during 
the following periods of time: 

Lot B Oong fed): 1909, Apr. 9 to Aug. 26; 1910, Apr. 7 to Aug. 
2; 1911, Apr. 21 to Sept. 8. Lot F (short fed): 1909, Mar. 19 to 
Aug. 5; 1910, Mar. 25 to June 23; 1911, Apr. 21 to Aug. 27. 



56 FEEDING BEEF CATTLE IN ALABAMA. 

4. The following average daily feeds of cake were given: 

Lot B Oongfed): 1909, 3.40 pounds; 1910, 3,45 pounds; 1911, 
3.60 pounds. Lot F (short fed): 1909, 4.39 pounds; 1910, 4.33 
pounds; 1911, 4.66 pounds. 

5. The steers in the B lot made a daily average gain of 1 .87 pounds, 
while thosQ in the F lot gained at the rate of 2.04 pounds each day. 

6. There were required 185 pounds of cottonseed cake to make 
100 pounds of gain in the B lot, while 220 pounds of cake were eat^i 
in the F lot to make the same gain. 

7. Wlien the pasture and cake are both charged against the gains, 
it cost $3.33 and $3.69 to make 100 pounds of gain in the B and F lots, 
respectively. 

8. The steers in the B lot cost on an average $3.05+ per himdred- 
weight at the beginning of the tests; they sold for $4.16+ per hun- 
dredweight at the close. The steers in the F lot cost $3.28+ per 
hundredweight and sold for $4.45+ per hundredweight. 

9. Clear average profits of $7.73 per steer in the B lot and $8.30 
per steer in the F lot were made. 

10. An additional advantage in selling the cattle early is that the 
pastures have an opportunity to make an extra growth after the 
cattle are taken off, thus providing feed for the early winter months. 
In fact, this is probably the chief advantage to be secured in selling 
cattle at an early date. 



ADDITIONAL COPIES of this pabllcatkm 
-Lx. may bo prooared from the BUPXBiNTEafD- 
KNT OP Documents, Ooverament I'riating 
Offloe, WaahiDgton, D. C, at 10 oonU per oopy 




,36 

U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF ANIMAL INDUSTRY— Bulletin 160. 

A. D. MELVIN, Chbj » flinuu. ^'V j'. 



THE CARE OF THE FARM EGG. 



HARRY M. LAMON and CHARLES L. OPPERMAN, 

Junior Animal Husbandmen, Animal Husbandry Division, 



BUREAU OF AiriMAL IIVDUSTRT. 



Chief: A. D. Mblvin. 

Auistavl Chief: A. M. Farrinoton. 

Chief Clerk: Charles C. Carroll. 

Animal Husbandry Division: George M. Rommel, chief. 

Biochemic Division: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsay, chief. 

Meat Inspection Division: R. P. Steddom, chief. 

Pathological Division: John R. Mohler, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Division: B. H. Ransom, chief. 

Experiment Station: E. C. Schroeder, superintendent. 

Editor: James M. Pickens. 



additional copies of this pablioaikm 
XI. may be prooiired from the Supkbintknd- 
ENT OF Documents, Oovemment Printliig 
Offioe, Washington, D. C. , at 15 cents per copy 



LETTER OF TRANSMITTAL. 



U. S. Depabtment of Agriculture, 

BXTREAU OP ANIBiAL INDUSTRY, 

Washington, D. C, September 7, 191S. 

Sir: I have the honor to transmit for publication as a bulletin of 
this bureau the accompanying manuscript entitled ''The Care of the 
Farm E^," by Messrs. Harry M. Lamon and Charles L. Opperman 
of the Animal Husbandry Division of this bureau. The work 
described is a continuation of the investigations into the egg trade 
which has been under way for several years. 

In 1908 a careful survey of the conditions surrounding the trade 
was made, and the results were published as Circxilor 140, "The Egg 
Trade of the United States," wherein it was shown that there was a 
very heavy loss in the egg output, nearly all of which was attributed 
to improper methods of handling on the farm and at the country 
store. TTtu3 loss was estimated to be fully 17 per cent of the total 
value, or $45,000,000 per annum. 

In 1911 Bulletin 141, ''The Improvement of the Farm Egg," was 
issued, one of the main objects of which was to emphasize the impor- 
tance of the "loss-off" or quality system of trading in eggs. The 
present paper is supplemental to Bulletin 141 and makes a special 
feature of the value of producing infertile rather than fertile eggs. 

Respectfully, 

A, D. Melvin, 

Chief of Bureau. 
Hon. James Wilson, 

Secretary of Agriculture. 



INTRODUCTORY NOTE. 



The egg investigations of 1910, which brought about the inaugura- 
tion of the '4oss-oflF'' or quality system of buying eggs in Kansas, 
resulted in marked improvement in the quaUty of the eggs marketed 
from that State. The work of 1911 was devoted to keeping up the 
interest in the movement and to the study of the effect of farm condi- 
tions on the keeping quality of eggs, the results of which are pre- 
sented herewith. The 1910 work emphasizes the effectiveness of 
organization as a means to improve the egg output of a community; 
the work of 1911 shows how the farmer may assure himself of maxi- 
mum returns for his eggs by taking proper care of them and by 
proper management of his flock. 

While the 1911 work was not, as some claim, a ** discovery" of the 
superior keeping quahty of the infertile egg, the authors deserve the 
credit for focusing public attention on the fact. Of the loss of 
$45,000,000 or more in the annual value of our egg crop, due to poor 
quality, at least one-third, or $15,000,000, is due to ''blood rings." 
A blood ring is caused by the development of the embryo of a fertile 
^g subjected to heat and its subsequent death. No embryo can 
develop in an infertile egg, no matter how long it may be subjected 
to heat, because it is not fertile. Therefore a blood ring is impossible 
in the infertile egg; and by the removal of male birds from the flock 
as soon as the hatching season is over, and the segregation of young 
cockerels, no loss from blood rings will be experienced. 

Unless cooled at once and kept cool, a fertile egg will spoil in hot 
weather almost as quickly as raw milk, and the purchaser of fertile 
eggA, even on the ''loss-off" basis, whether he be the country-store 
merchant, the packer, or the consumer, has no assiurance whatever 
against more or less loss. An infertile egg will keep ; a fertile one 
will not. It therefore does not require a great stretch of the imagi- 
nation to realize what effect the country-wide production of infertile 
eggs would have on our food supply. 

Some of the loss due to ''rots" and "spots," as shown in this 
bulletin, is caused by contamination in the nest and is largely, if not 
entirely, preventable. Both fertile and infertile eggs may be dam- 
aged in this way, although infertile eggs are less susceptible than 

fertile ones. 

5 



6 INTBODUCTOBY NOTE. 

The propaganda work in Kansas has now been turned over to the 
Kansas State Agricultural College and Experiment Station at Man- 
hattan, and the Animal Husbandry Division is now concentrating 
its efforts on the spread of the good-egg movement to other States, 
oi^anizations haying been effected abeady in Michigan and Minnesota. 
I jBrmly believe that if the egg-producing States generally will take 
up the matter of buying on a quality basis and the farmers are shown 
how to care for their eggs properly, especially to sell only infertile eggs 
during the summer months, the housewife will soon be able to ob- 
serve a decided improvement in the quaKty of the eggs which she 
buys without having paid more for them than formerly. The 
means to improve the quality of the farm egg are so simple and 
inexpensive that anyone who keeps a flock of chickens should be 
able to apply them. In this connection the reader's attention is 
particularly directed to the five rules at the close of the bulletin. 

In the investigations discussed in this bulletin the authors received 
a great deal of assistance from citizens of Kansas and from State 
officials, which has been greatly appreciated. Mr. Alfred R. Lee, of 
this division, also assisted part of the time in the investigation. 

George M. Rommel, 
Chief of the Animal Husbandry Division. 



CONTENTS. 



Pate. 

Introduction 9 

The giadixig of egga 10 

Methods used in conducting the experiments 12 

Description of the experiments 15 

A. Keeping eggs in dwelling house 15 

B. Keeping eggs in cyclone cave 16 

Inefficient storing facilities on the fann 16 

G. Eggs placed in nests provided for laying hens 17 

D. Placing eggs under sitting hen 18 

E. Placing eggs under comcrib .*. 18 

F. Eggs placed in nest in weeds or underbrush 18 

G. Eggs placed in nest on straw stack 18 

H. Eggs placed in stolen nest 19 

Results of the experiments 19 

A. The house experiments 20 

B. The cyclone-cave experiments 23 

C. Experiments with eggs placed in nests for layers 24 

D. The sitting hen experiments 27 

E. The comcrib experiment 27 

F. The weed-nest experiment 30 

G. The straw-stack experiment 32 

H. The stolen-nest experiments 34 

Comparison of clean fertile eggs under seven different conditions 36 

Comparison of clean infertile eggs under six different conditions 38 

A comparison of the losses in clean fertile and infertile ^gs under all the experi- 
mental conditions 40 

Relation of temperature to deterioration in eggs 42 

Summary 45 

Appendix — Detailed record of cyclone-cave experiment 47 

7 



ILLUSTRATIONS. 



PLATES. 

Plate I. Fig. 1. — ^Thermograph recording temperature and humidity. Fig. 
2. — ^Thermograph recording temperature only. Fig. 3. — ^Thermo- 
graph in operation 16 

II. Fig. 1. — A typicsA weed nest. Fig. 2. — Stolen neet in hollow apple 

tree. Fig. 3. — A cyclone cave. Fig. 4. — ^A nest in a straw stack. . 16 

III. Fig. 1.— Normal fresh egg. Fig. 2.— Fresh egg showing blood clot. 

Fig. 3. — Fertile egg after 24 hours of incubation. Fig. 4. — Infertile 
egg after 24 hours of incubation 46 

IV. Fig. 1. — Fertile egg allowed to die after 36 hours of incubation. 

Fig. 2. — Infertile egg after 36 hours of incubation. Fig. 3. — Fertile 
egg after 48 hours of incubation. Fig. 4. — Infertile egg after 48 

%our8 of incubation 46 

V. Fig. 1. — Fertile egg after 72 hours of incubation. Fig. 2. — Infertile 
^g after 72 hours of incubation. Fig. 3. — Fertile egg after 7 days 
of incubation. Fig. 4. — Infertile egg after 7 days of incubation. ... 46 
VI. Fig. 1. — Fertile egg allowed to die after 72 hours of incubation. 
Fig. 2. — Mixed rot. Fig. 3. — Egg showing mold spot. Fig. 4. — Egg 
showing plain spot 46 

TEXr FiaURES. 

Figure 1. — Comparative losses in fertile and infertile eggs from farm to market. 40 
2. — Thermograph record showing temperature in parlor of dwelling 

house during one week of moderately cool weather 43 

3. — ^Thermograph record showing temperature in parlor of dwelling 

house during one week of hot weather 44 

4. — ^Temperature and humidity records in house week of July 1 to 8, 

1911 44 

5. — ^Temperature and humidity records in house week of June 24 to 

July 1,1911 44 

6. — ^Temperature and humidity records outside week of June 24 to 

July 1,1911 45 

7. — Temperature and humidity records from Aug. 5 to 12, 1911 45 

8. — Thermograph record showing temperature and length of time eggs 

were held in town and in transit to packing house 45 

8 



THE CARE OF THE FARM EGG. 



INTRODUCTION. 

Since the poultry and egg industry of this country has assumed 
the enormous proportions indicated by the two last national cen- 
suses, 1900 and 1910, there has been a demand for and a growing inter- 
est in improved conditions and' a need for a broader knowledge of 
the underlying principles of the industry. The State agricultural 
colleges and experiment stations have established departments of 
poultry husbandry for both teaching and research work. The 
experimental departments have given their attention to the various 
questions involved in the housing, feeding, breeding, and general 
management of poultry, while the instruction departments have 
built up practical coiu^es in this branch of animal husbandry and 
have also assisted in disseminating the knowledge gained from the 
results of experimental work. Thus on every hand we can see an 
interest being manifested in improving the conditions in all branches 
of poultry work. 

One of the most important of these is the production and market- 
ing of eggs. Every year there is a loss of millions of dollars in bad 
^gs, the direct result of haphazard methods of production, market- 
ing, and shipping which are now in vogue in many States. The 
greatest part of this loss is due mainly to ignorance or indifference 
on the part of the farmer and producer, and only a small part is 
caused by carelessness on the part of the buyer and shipper. In 
many instances the buyer is indirectly responsible, for when he buys 
eggs by the case-count system, as many of them do, he is encouraging 
the producer to be careless. in gathering and marketing the e^s, 
since he pays him for anything that has an intact shell. The con- 
scientious producer, however, will not try to shield himself under 
this pernicious system, so it is very much to his advantage to aid in 
the improvement of the commercial egg. He may not receive any 
extra compensation at the very start, but just as surely as he makes 
an organized effort to furnish the trade with strictly fresh eggs so 
surely will the competition in trade make it possible for him to 
dispose of his superior product at an increased profit. 

It was with the view of determining the causes of the enormous 
loss in eggs, and if possible working out methods for its elimination, 
that the Department of Agriculture, through the Bureau of Animal 

65700^— Bull. 160—13 2 9 



10 THE CARE OF THE FARM EGG, 

Industry, undertook a thorough investigation of the problem. Two 
publications,* one giving a bird's-eye view of the situation in several 
States and the other dealing specifically with the conditions in the 
State of Kansas, have already been issued. It was the knowledge 
gained through this general survey of conditions that suggested the 
imdertaking of the experimental egg work set forth in the present 
paper. 

THE GRADING OF EGGS. 

Where eggs are handled in large quantities thei^ are certain grades 
by which they are sorted and either retained for market purposes or 
rejected as useless. A brief description of these grades and the 
characteristics by which they are detected is given below. 

Fresh egg, — ^An egg to be accepted as a first, or fresh egg, must be 
newly laid, clean, of normal size, showing a very small air cell, and 
must have a strong, smooth shell, of even color and free from cracks. 
With the exception of the air cell, which is only visible through the 
aid of the candle, these are the points by which eggs are graded in 
the early spring, at which time they are quite uniform in quality, 
thereby making candling unnecessary. 

Checks, — ^This term applies to eggs which are cracked but not 
leaking. 

Leakers, — As indicated by the name, this term applies to eggs 
which have lost a part of their contents. 

Seconds. — ^The term "seconds" applies to eggs which have dete- 
riorated to a sufficient extent as to be rejected as firsts. They are, 
however, of a high enough quality to be used for human consump- 
tion. The several classes of eggs which go to make up this grade 
may be defined as follows: 

(a) Heated egg: One in which the embryo has proceeded to a 
point corresponding to about 18 to 24 hours of normal incubation. 
(See PL III, fig. 3.) In the infertile egg this condition can be recog- 
nized by the increased color of the yolk; when held before the candle 
it will appear heavy and slightly darker than in the fertile egg. 

(6) Shrunken egg: This class of seconds can be easily distinguished 
by the size of the air cell. It may occupy from one-fifth to one-third 
of the space inside the shell. The holding of eggs for a sufficient 
length of time to allow a portion of the contents to evaporate is the 
main cause of this condition. 

(c) Small egg: Any egg that wiD detract from the appearance of 
normal eggs on account of its small size will come under this class, 
although it may be a new-laid egg. 

X Hastings, Milo M. The egg trade of the United States. Bureau of Animal Industry Circular 140. 
Washington, 1909. 

Lamon, Harry M., and Opperman, Charles L. The improvement of the farm egg. Bureau of Animal 
Industry Bulletin 141. Washington, 1911. 



THE «BADING OF EGGS. 11 

(d) Dirty egg: Fresh eggs which have been soiled with earth, 
droppings, or egg contents, or badly stained by coming in contact 
with wet straw, hay, etc., are classed as seconds. 

(e) Watery egg: Those in which the inner membrane of the air cell 
is ruptured, allowing the air to escape into the contents of the egg, 
and thereby giving a watery or frothy appearance. 

(f) Presence of foreign matter in eggs: In Plate III, figure 2, is 
given an excellent illustration of this class of eggs. The small dark 
streak across the yolk is a clot of blood. This condition is found in 
many fresh-laid eggs. Often eggs are laid which show small clots 
about the size of a pea. These are sometimes termed ''liver" or 
''meat" spots. 

(g) Badly misshapen eggs: Eggs which are extremely long or very 
flat, or in which part of the shell's siu^ace is raised in the form of a 
ring; in other instances a number of hard wart-like growths appear 
on the outside of the shell. 

Spots. — Eggs in which bacteria or mold growth has developed 
locally and caused the formation of a lumpy adhesion on the inside 
of the shell. There are three weU-recognized classes of mold spots, 
namely, white, brown, and black. In cases where an infertile egg 
has been subjected to natural heat for a sufficient period of time, the 
yolk will often settle and become fixed to the membrane. This con- 
dition might be termed a *' plain spot." In Plate VI, figures 3 and 
4, are shown typical specimens of black mold and plain spot eggs. 

Blood rings. — Eggs in which the embryo has developed to a suffi- 
cient extent so that it is quickly recognized wlien held before the 
candle. It has been found that it requires between 24 and 36 hours 
of incubation under a sitting hen to produce this condition. Good 
illustrations of these conditions are shown in Plate IV, figures 1 and 
3, and in Plate V, figure 1 . 

Bots. — Eggs which are absolutely unfit for food. The different 
classes of rots may be defined as follows : 

(a) Black rot: This is the easiest class of rots to recognize and 
consequently the best known. When the egg is held before the can- 
dle, the contents have a blackish appearance, and in most cases the 
air cell is very prominent. The formation of hydrogen-sulphid gas 
in the egg causes the contents to blacken and gives rise to the char- 
acteristic rotten-egg smeU, and sometimes causes the egg to explode. 

(6) White rot: These eggs have a characteristic sour smell. The 
contents become watery, the yolk and white mixed, and the whole 
egg offensive to both the sight and the smell. It is also known as 
the "mixed rot." 

(c) Spot rot: In this case the foreign growth has not contaminated 
the entire egg, but has remained near the point of entrance. Such 
eggs are readily picked out with the candle, and when broken show 



12 THE CARE OF THE F^M EGG. 

lumpy particles adhering to the inside of the shell. These lumps 
are of various colors and appearances. It is probable that spot 
rots are caused as much by mold as by bacteria, but for practical 
piuposes the distinction is unnecessary. 

To all intents and purposes the spot rot as explained above is 
practically the same as the brown and black spots described under 
the general head of *' Spots." The spot rot is also placed under the 
general head of rots simply because some candlers will call it a spot, 
while others designate it as spot rot. Pink and blood rots are names 
which are also appUed to certain classes of rotten eggs, the pink rot 
deriving its name from the peculiar pinkish color of the contents 
when held before the candle. The same thing is true of the blood 
rot, which is bloody or red in appearance. 

MBTHODS USED m CONDUCTING THE EXPERIMENTS. 

The plan of the work was to determine, in so far as could be shown 
by the candle, what deterioration took place in eggs when retained 
under actual conditions on the farms, in the coimtry store, and 
during transportation. In choosing the field for the work careful 
consideration was given to the following points: A State where the 
production and marketing of eggs was an important factor, a location 
in that State where the cooperation of several farmers could be 
secured, and a town that was far enough from a central coUectiog 
point (or packing house) so that the effect of typical transportation 
conditions could be observed. 

The eggs used in the various experiments were collected at a stated 
time each day from several farms and started in the experiment 
within an hour or two thereafter. Every egg was supposed to be 
absolutely fresh when entered in the experiments, and in aJl about 
10,000 eggs were used during the season's work. 

The six following classes of eggs were used: Clean fertile, dirty 
fertile, washed fertile, clean infertile, dirty infertile, and washed 
infertile. 

Clean fertile eggs were normal fresh eggs produced by the farm 
flocks, on free range, with several mature male birds present during 
the entire season. Dirty fertile eggs were fresh eggs from the same 
flocks^ but which before entering the experiments were artificially 
dirtied with barnyard mud to conform as nearly as possible with the 
natural dirty egg. Washed fertile eggs were fresh eggs from the 
above flocks which were thoroughly washed previous to being put in 
the experiments. In washing the eggs they were allowed to remain 
in a basin of water for a few moments and then well rubbed with an 
ordinary wash cloth and immediately dried with a towel. It is the 
general opinion that washed eggs do not keep as well as unwashed, 
and it was to determine this point that these eggs were used. 



METHODS tJSED IK CONDUCTING fiXPEillMENTS. 13 

The three classes of infertile eggs used were identical with the fer- 
tile eggs, with the exception of being produced by flocks where the 
male birds were removed three weeks previous to using the eggs. 
It will be noted from the tables on the succeeding pages that experi- 
mental work with infertile eggs did not begin until after the 1st of 
June. This is due to the fact that under most farm conditions 
it would be impracticable to attempt to produce infertile eggs during 
the earlier spring months, as this is the season when the hatching 
and rearing of the coming year's flock must be attended to. 

Every egg used was dated, which made it possible to secure a 
complete history of the egg from the time it was produced until 
it reached its final destination. This method of dating made each 
day's eggs in a given experiment a time experiment also. For 
example: A seven-day experiment having a given number of fresh 
eggs added each day, and these being dated, we obtained the influence 
of a certain environment for one, two, three, four, five, six, and 
seven days. 

In Plate I, figures 1 and 2, is given a photographic reproduction 
of the thermographs used in connection with the work. The machine 
shown in figure 1 was located at the farm where the bulk of the work 
was carried on and used for recording the different temperatures and 
humidity. In figure 3 is a view of the apparatus in actual operation, 
the thermograph being inclosed in the box. The oilcloth covering 
was used to prevent the rain from entering the box and also to 
divert the direct rays of the sun. It was so arranged, however, 
that free circulation of air was not interfered with. A machiae 
similar to that shown in figure 1 was used in the rooms of the dwelling 
house where certain experiments were conducted. The machine 
shown in figure 2 is constructed to record temperature only. It 
accompanied each shipment of eggs from the time it arrived at the 
country store, and while on the train, thereby furnishing a complete 
chain of temperature records for the experiments from the time the 
eggs were produced until they reached the packing house. 

When the experiments were completed at the farm, which was in 
most cases seven days, the eggs were packed iu ordinary 30-dozen 
cases, care being exercised to see that each experiment was kept 
separate. The transportation to town was by means of a team and 
buggy. After arriving in town, the eggs were candled immediately 
and an individual record made of the condition of each egg. This 
first candling represents the deterioration which occurred on the 
farm. The eggs were then repacked and held under typical country- 
store conditions for from 24 to 48 hours. The next operation 
was recandling, a similar record being made as above, showing the 
deterioration which took place while being held in the country store. 
They were then repacked and placed in an open stock car (the style 



14 



THE CABE OF THE FABM £g6. 



of car used in that locality for shipping eggs and poultry) where they 
remained for about 12 hours before starting on their journey to the 
packing house, by local freight, a distance of 78 miles, requiring about 
10 hours for the journey. The reason for placing the eggs in the car 
12 hours preyious to starting was due to the fact that the car was 
shipped early in the morning and it was often impossible for the 
merchants and local shippers to deliver the eggs at such an early hour. 

After reaching the packing house the eggs were removed from the 
car in accordance with the usual custom and again candled. This 
third and last candling gave the deterioration which occurred 
during railroad transportation. The experiment, in so far as this 
paper is concerned, was then complete. The above methods of 
procedure were practically identical for all the experiments made 
diuring the entire season, and unless some special deviation occurred, 
no further mention will be made of them. 

A sample candling report is here presented: 

First town (xmdling report. Date, Juru 5, 1911, 



Date laid 


Junel. 


June 2. 


June 3. 


June 4. 


June 5. 


June 6. 

% 


June 7. 


Total. 






Firsts 


3 

1 


2 
2 
1 


3 
2 


3 

1 
1 


4 
1 


5 


5 


25 


floconds 


7 


Cracked 






2 


Tjeakers 














SDOtS 


1 














1 


Blood rings 
















Rots 




































Total 


6 


5 


5 


5 


5 


5 


5 


35 







Second town candling report. Datey June 10 ^ 1911. 



Firsts 


1 
3 


1 
3 
1 


2 
3 


2 
2 
1 


3 ' 
2 


4 
1 


4 
1 


17 


Seconds 


15 


Cracked 


2 


Leakers 












Snots 


1 






::::::::::::::::::::: 




1 


Blood rtnes 














Rots 




































Total 


5 

• 


5 


5 


5 


5 


5 


5 


35 







Final candling report at packing house. Date, June 1£, 1911. 



Firsts 






1 
4 


1 
3 

1 


2 
3 


3 
2 


4 

1 


11 


Seconds 


4 


4 

1 


21 


Cracked 


2 


Leakers 














Snots 


1 














1 


Blood rinss 














...• 


Rots 




































Total 


6 


5 


5 


5 


5 


5 


6 


35 







In assembling the data connected with the work, the forms shown 
below were used. As will be seen upon inspection the card was used 
for recording the details concerning the experiment and the candling 



DESCRIPTION OF THE EXPERIMENTS. 15 

report for a record of the eggs. After being filled out, the card and 
report were fastened together and filed away for future reference. 

[Front of card.] 
[United States Department of Agriculture, Bureau of Animal Industry.] 
POULTRY AND BOG MARKBTINO INVESTIGATIONS— HANDLING BOGS. 



Obenrver.. Date Experiment No. 

Statement of experiment 



Material used. 



Eggs produced by Farmers' Card No 

Date laid Where held 

Container and its condition How long held 

Date and hour left farm for market 

Haul to market or store by ftomer: Tlifte Miles 

Container 

Wagon Condition of road 

Hani to market pt store by egg collector or huckster: Card No Time Miles. 

Container 

Wagon Condition of road 

Store or buyer to whom sold Card No 

Date reoeiyed at store How long held 

Where held Container and its condition , 

How packed for shipment Kind and condition of cases and fillers 

Date and hour left store for station Length of haul 

Where held at station How long held Covered or uncovered. 

Size of shipment Time put on car 

Kind of car Eggs alone or eggs and poultry in car , 

Length and time of railroad haul Reloaded 



[Back of card.] 



Date and time of arrival at packing house 

How handled at packing house: How long before put in cooler Temperature of cooler 

Candling before or after cooling O rading Packing 

Time held How shipped 

Date and hour put in car for shipment Kind of car Time of shipment. 

To whom shipped Date of shipment 

Remarks 



DESCRIPTION OF THE EXPERIMENTS. 

The question of selecting the proper conditions for the carrying 
out of the various experiments was one of vital importance, and it 
was only after careful consideration of the actual known conditions 
on the farms that the experiments described below were outlined. 
Experiments A and B were conducted with fertile and infertile 
dirty, washed, and clean eggs; Experiments C, E, F, and G with 
fertile and infertile clean and dirty eggs, while in Experiments D and 
H supposedly fertile eggs were used. 

A. KEEPING EGGS IN DWELLING HOUSE. 

The procedure followed in conducting an experiment with clean 
fertile eggs was as follows: Five eggs laid on a certain day were put 
in a clean receptacle (small grape basket) and placed in the parlor 
of the house (no artificial heat). Five fresh eggs were added each 



16 THE CARE OF THE FABM EGG. 

succeeding day until the experiment was completed at the farm, 
which was seven days in all cases except ''stolen nest" and ''under 
sitting hens." After once being put into the receptacle, the eggs 
were never removed from the room until they were packed and 
transferred to town. A constant record of temperature and humid- 
ity for the experiments was obtained by the use of a thermograph. 

B. KEEPING EGGS IN CYCLONE CAVE. 

The procedure for this experiment was identical with that given 
above, with the exception that instead of using a thermograph, an 
ordinary thermometer was employed, the temperature record being 
secured by reading three times daily. The use of the thermograph 
in this instance was unnecessary, as previous experience had shown 
that the temperature of the cave did not vary more than three or 
four degrees in a week, such a condition making it possible to pro- 
cure a very accurate temperature record by the use of the thermometer* 

In the section of the coimtry where these experiments were con- 
ducted, many farmers did not have good, clean, dry cellars under 
their houses, but nearly all had what is known as "cyclone caves," 
in which are often kept the eggs produced on the farm. The con- 
ditions in many of these caves are as good as in the ordinary dry, 
unheated cellar. Plate II, figure 3, is a photograph of a cyclone 
cave, showing the entrance with doors open. These caves are often 
ventilated by a small window at the end opposite the door, and by 
a pipe leading through the top of the roof. 

INEFFICIENT STORING FACILITIES ON THE FARM. 

It has been pointed out in a previous publication (Bureau of Animal 
Industry Bulletin 141) that inefficient storage facilities on the farm 
are a serious difficulty with which the farmer's wife often has to con- 
tend, as a great many of the country homes in Kansas do not have 
dry, cool cellars, and when the thermometer begins to register from 
100° to 106° F. there is no good place to keep perishable produce. 
To overcome this difficulty use is often made of the "cyclone cellar," 
or cave. In some instances these caves are of concrete construction 
throughout, and on such farms very little difficulty is experienced 
in keeping eggs in good condition. Some of these caves, however, are 
nothing more than oblong holes in the ground over which a rough 
gable roof is built. The soil which has been excavated to make the 
cave is thrown over this roof, and thoroughly packed so as to make it 
cool and practically waterproof. Caves of such construction are 
very hard to keep clean on account of the dampness and mold, which 
are always present when dirt walls and floor are used, and conse- 
quently they are very undesirable as a storage room for e^s. Damp- 
ness is conductive to the rapid development of mold and bacteria, 



3. DUT. OF MDIOULTtlHC. 



—Thermograph Recoroinq Temperature and Humidity. 



Fia 2.— THEftMooRAPH Recordino Temperature only. 



FiQ. 3.— Thermograph in Operation. 



UlllUI. (HDUtTBI, u. S. DE". O' AomcuLTuni 



DESCRIPTION OF THE EXPERIMENTS. 17 

and consequently eggs kept in these caves are much more likely to 
show deterioration than if they were held in a dry room at the same 
temperature. 

C. EGOS PLACED IN NESTS PROVIDED FOR LAYING HENS. 

There can be no doubt of the fact that the annual loss in the 
United States on account of eggs becoming absolutely unfit for ' 
human food (''rots" and ''spots '') amounts to many millions of 
dollars. This much being conceded, the next problem is to ascertain 
when, where, and how this enormous deterioration is accomplished. 

In this experiment, and in the others to follow, the object sought 
is definite knowledge as to the manner in which these inferior grades 
of eggs are produced. The fact that it is practically impossible, 
within a period of a few days and in normal weather, to produce spots 
and rots under the conditions of the two preceding experiments, made 
it necessary to typify in an experimental way the more abnormal condi- 
tions under which eggs might be subjected on the farm. Thus, in this 
experiment one of the bad effects due to infrequent gathering is seen. 

With sitters in the flock, — On practically all farms during the spring 
and summer there are a certain number of broody hens which, if not 
used for hatching purposes, will spend more or less of their time 
sitting on the eggs in the nests utilized by the layers. This is true 
also, but in a less degree, even when an effort is made to break up 
the habit by taking the hens from the nests, during the day or at 
night, and placing them in yards or coops where there are no nests. 

In this experiment the sitters were handled according to the usual 
custom on the farm — that is, they were removed from the nests every 
day or so and confined in a large coop for several days and then set 
at Uberty. A daily record was kept of the number present on the 
nests so as to observe the rate of deterioration when few were present 
as compared with that when the sitters were numerous. 

The method of conducting this experiment was as follows: Five 
eggs laid on a certain day were placed in several nests which were 
provided for the laying hens. Five fresh eggs were added each 
succeeding day until the experiment was completed at the farm. 
The time for this experiment was sevei^ days. After the eggs were 
placed in the various nests they were not removed until packed and 
transferred to town. 

No sitters on the nests. — After making provision for obtaining infor- 
mation as to the per cent of deterioration in eggs placed in nests for 
layers, with sitters present, it seemed desirable to investigate the 
problem from another standpoint, namely, that of a duplicate experi- 
ment having no sitters present. In this respect the cooperation of a 
farmer having a flock of White Leghorns was secured. This breed 
being nonsitters made it possible to carry out the desired project. 

65700°— Bull. 160—13 3 



18 THE CARE OF THE FABM EGG. 

Care was exercised to see that any fowl showing a disposition to 
become broody was immediately confined. The method of conduct- 
ing this experiment was exactly the same as that with the sitters 
on the nests. 

D. PLACING EOGS UNDER SITTING HEN. 

This experiment was instituted to determine accurately from a 
practical standpoint the period of time required to produce a blood 
ring that could be detected by the aid of the candle. Any changes 
occurring before this stage was reached were also observed and 
recorded. The experiment was divided into four parts, showing 
the influence of natural incubation for 24 hours, 36 hours, 48 hours, 
and 72 hours. 

The procedure for the tests was as follows: From 10 to a dozen 
fresh fertile eggs were placed under a sitting hen and allowed to 
remain there for the specific time required by the test. They were 
then removed to the room in the dwelling house where Ebcperiment A 
was carried on, and kept there until the experiment was completed 
at the farm. As soon as one lot of eggs was removed from under the 
hen a fresh lot was substituted, and the experiment carried on 
continually in this manner. Separate tests with infertile eggs were 
also carried on. 

E. PLACING EGGS UNDER CORNCRIB. 

In this experiment five clean, fertile, new-laid eggs were placed on 
the earth underneath the corncrib, and protected by means of an 
open-mesh wire hood. Five fresh eggs were added for each successive 
day until the experiment was completed at the farm. The eggs were 
never removed from under the corncrib until the experiment was 
ended. 

F. EGGS PLACED IN NESTS IN WEEDS OR UNDERBRUSH. 

In selecting the location for these nests care was exercised to have 
the conditions as natural as possible, and in most cases the locations 
decided upon were those that had already been chosen by the hens 
themselves. In conducting the experiment the following methods 
were used: Five clean fertile eggs laid that day were placed on the 
earth in the weeds or underbrush, and protected by means of an open- 
mesh wire hood. Five fresh eggs were added for each successive day 
until the experiment was completed at the farm, the time in this case 
being seven days. The eggs after being placed in the nests were 
never removed until packed and transferred to town. 

G. EGGS PLACED IN NEST ON STRAW STACK. 

The procedure in this case was similar to that given in the preceding 
experiment, with the exception that the eggs were put in nests on 
the straw stack instead of on the earth. 



BBSULTS OF THE EXPERIMENTS. 19 

H. EGGS PLACED IN STOLEN NEST. 

It is a common occurrence for the farm hen to locate her nest in 
some out-of-the-way place which is not likely to be discovered. 
These are designated ^*stolen nests." After choosing a location, she 
will lay from 10 to 15 eggs, and then start to sit. It often so happens 
that rfter sitting on the eggs for several days she will become indis- 
posed and abandon the nest. In due course the eggs will be dis- 
covered by some of the members of the household, and if they are 
not educated as to what constitutes a good egg, they will put them 
in with the rest of the eggs that are sent to market. This is one of 
the channels through which thousands of dozens of bad eggs are 
placed on the market. 

To secure knowledge concerning the quality of these eggs, the 
following method was adopted: After locating a stolen nest, the eggs 
of -unknown history would be removed and a marked nest egg left. 
From that time on the nest was visited each day, and the eggs dated 
as they were laid. The hen was allowed to lay until she started to 
set, at which time the eggs were removed and transferred to town, 
where they were candled. The object was not to note the effect of 
steady incubation, but rather the condition of the eggs just previous 
to the time the hen would desire to set. Such data as temperature, 
rainfall, and the number of clear deLjs were carefully recorded for 
each experiment. 

RESULTS OF THE EXPERIMENTS. 

Before discussing the results of the various experiments, it will be 
well to outline briefly the system followed in condensing the tables. 
In the Appendix at the end of this bulletin are given the detailed 
data from which the condensed tables referring to the cyclone-cave 
experiment were compiled. It may here be noticed that experi- 
ments Nos. 43, 44, and 45 all began on May 13 and ended at the farm 
on May 20. Each of these experiments, however, had to do with a 
certain class of fertile ^gs with which tests were being conducted 
in the cave. In the condensed reports (see Tables 1, etc.) we have 
the total results for a part of the season, June 17 to August 26, for 
the fertile and infertile eggs of each of these different experiments 
given in the same general form as that used for recording the data 
of a seven-day experiment in the Appendix. In drawing conclusions 
from the condensed reports, it is obvious that cognizance can not be 
taken of the specific deterioration occurring in an experiment during 
a seven-day period of extremely hot or moderately cool weather. 
This point, however, will be taken up in another part of the paper. 
The fact that the results of the condensed reports are a true repre- 
sentation of the loss which the producer who allowed the eggs to 



20 THE CABE OF THE FABM EGO. 

remain in any of the various conditions would have to bear, makes 
it possible to reach conclusions that have a practical application. 

The price allowed in this work for first , or fresh, eggs is 15 cents 
per dozen, and for seconds and cracks, 9 cents. Leakers, spots, blood 
rings, and rots are figured as a total loss. The above prices will 
correspond favorably with those allowed by buyers who purchased 
on the loss-off system during the season that the experiments were 
conducted. The per cent of loss which is given in the last column of 
the table is figured from the actual loss in dollars and cents, since this 
is the only basis by which the loss borne by the producer can be 
aptly represented. Loss at the packing house represents total loss 
from farm to packing house. 

The reader will recall that in the descriptions of the different experi- 
ments mention was made of carrying on tests with dirty fertile and 
infertile eggs in some of the experiments. This was done for several 
weeks at the b^inning of the season, but the results obtained were 
not considered of enough importance to continue them as first planned, 
and it was decided to continue them in the ''house'* and ''weed-nest" 
experiments only. This was done in order that whatever difference 
there might be in the keeping qualities of dirty and clean eggs might 
be observed, and the retention of them in one inside and one outside 
experiment was considered sufficient to furnish such data as were 
desired. 

A. THE HOUSE EXPERIMENTS. 

The results obtained from the house experiments, as set forth in 
Table 1, may be noted as follows: 

1. That all classes of eggs kept in this environment showed a much 
higher per cent of loss than those which were kept in the cyclone 
cave. This increased loss is accounted for by the fact that the daily 
maximum temperature in the house was from 15^ to 40° higher than 
that of the cave. In the former the maximum temperature on two 
occasions reached 114° F., while in the latter it never exceeded 70° F. 

2. The class of eggs wherein the greatest per cent of loss occurred was 
that of dirty fertile, although the clean fertile were less than one-half 
of 1 per cent less. In no way, however, can this slightly increased 
deterioration be attributed to the fact that the eggs were dirty, for 
in practically every instance the development of floats, blood rings, 
and rots were the causes of loss. Again, the variations in the losses 
of clean fertile, washed fertile, and dirty fertile were so slight when 
compared to each other that it would be impossible to say that the 
decreased or increased deterioration was caused through the eggs 
being clean, washed, or dirty. 

3. That clean infertile eggs, as was the case in the cave experiments, 
again proved superior to all other classes, the loss at the packing house 



BESULTS OF THE EXPERIMENTS. 21 

being from 17 to 25 per cent less than in the classes of fertiles, which 
decrease is due mainly to the absence of spots, blood rings, and rots. 
In view of the fact that infertile eggs should be sterile, it may seem 
peculiar to the reader that the above grades manifested their pres- 
ence in this class of eggs. This may be explained, however, by the 
fact that after the middle of August the activity of the young cockerels 
is such that it is rather difficult to find a farmer who has a flock of 
chickens that are producing 100 per cent of infertile eggs. It is a 
condition that exists under practical conditions and cognizance of it 
must therefore be taken in a problem of this nature. In other words, 
it would detract from the value of the work to use 100 per cent infer- 
tile eggs at the season of the year when the farmer has to contend 
with a certain per cent of fertile ones. The farmer must retain a 
certain number of cockerels for breeding purposes, and if he is to pro- 
duce strong vigorous males it is obvious that they can not be confined 
in small coops or yards. 

4. Of the three classes of infertile eggs, the variations in loss are of 
such a minor nature that they can not be regarded as significant. 

5. A comparison of the percentage of seconds in the three classes of 
fertile eggs with those in the same classes of infertile will show that 
during the seven days the eggs were held at the farm the fertile eggs 
produced the greatest proportion of seconds. This is also true of the 
second candling, but in the third and final candling the percentage of 
seconds was greater in the infertile eggs. This* apparent decrease in 
the fertile seconds is due to the fact that many of the eggs which were 
seconds just before leaving town deteriorated to such an extent 
during transportation that they were graded as blood rings, etc., when 
candled at the packing house. This change, of course, did not take 
place in the infertile classes, which clearly explains the variation. 
As has been mentioned before, the infertUe seconds were far superior 
to the fertile. 

The results of this experiment may be briefly summarized in the 
following statements : 

(a) An unheated room in a dwelling house is not as good a place to 
keep eggs as the cyclone cave, or dry, unheated cellar. 

(6) The condition of clean infertile eggs, when candled at the 
packing house, was better than that of any other class. 

(c) The keeping qualities of the three classes of fertile eggs are 
practically the same, which is also true for infertile during the time of 
the experiment. 

(d) If the producer is to realize the maximum returns, he can not 
afford to keep fertile or infertile eggs in the house during the warm 
season. 



22 



THE CARE OF THE FABH EOO. 



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BESXILTS OF THE EXPERIMENTS. 23 

B. THE CYCLONE-CAVE EXPERIMENTS. 

A perusal of Table 2, which deals with e^s retained in a cyclone 
cave, will show the following important points: (1) That with all 
classes of eggs, both fertile and infertile, there was practically no 
loss from the time the eggs were produced until they left town for 
the packing house, and after reaching the packing house the greatest 
loss, which was in the clean fertile class, did not exceed 19.8 per 
cent of the total value of the eggs. (2) That the loss occurring in 
clean and washed fertile eggs is nearly the same. A result of this 
kind would indicate that fertile eggs which had become soiled in the 
nest could be washed and retained in the cave without any serious 
deterioration taking place if the operation was performed in the 
manner herein described. It must be borne in mind, however, that 
in this case, while washed eggs stored under good conditions appar- 
ently kept as well as unwashed, the fact that contact with water 
tends to remove or dissolve the mucilaginous coating of the eggshell, 
thereby lessening the resistance to the invasion of molds and bac- 
teria and also allowing more rapid evaporation of the contents, 
makes such eggs inferior for storing purposes when compared with 
clean eggs. (3) That the infertile eggs proved their superior keeping 
qualities over all others. The important point to. be brought out in 
connection with infertile eggs is that the absence of fertilization 
makes it impossible for such eggs to develop iuto blood rings or 
chick rots, while in the fertile eggs these grades of deteriorated eggs 
comprise the great bulk of the loss. While the number and percentage 
of infertile seconds is only 10 per cent less than that of fertile, it is 
important that we thoroughly understand the great difference 
which exists in the quality of these two classes of seconds. For 
example, it will be sufficient to say that from 90 to 95 per cent of the 
infertile seconds were so designated on account of a slight shrinkage 
in the contents of the eggs, thereby causing the air cell to appear 
larger than that foimd in the fresh egg, while with the fertile seconds 
there was a very noticeable deterioration or change brought about 
by the development of the living embryo. In other words, there 
occurs no change in the former which would tend to render the egg 
unfit for food, while in the latter the composition of the egg is under- 
going a marked change through the development of life within the 
egg. These differences are well illustrated in Plates III, IV, and V. 
Furthermore, it may here be stated that the great differences in 
fertile and infertile seconds were much more noticeable when the 
eggs were kept under other conditions than in the cave experiments. 

The conclusions, so far as may be drawn from the data at hand 
are, first, that all classes of eggs retained in the cyclone cave showed 
a very small percentage of loss from the time they wore produced until 
they reached cold storage. Second, that clean infertile eggs proved 



24 THE CARE OF THE FABM EGO. 

superior to all other classes, and washed infertiles second best. 
Third, that clean and washed fertile eggs compared favorably with 
the same classes of infertile while retamed in the cave, but showed a 
tendency to deteriorate more rapidly during transportation from 
farm to packing house. 

C. EXPEBQCEirrS WriH EGOS PLACED IN NESTS FOB LAYERS. 

From Table 3, which shows the results of these experiments, we 
may note the following points: 

1. In both the experiments with clean fertile eggs the resulting loss 
was far in excess of any other condition. In the first case, where 
sitters were present, the high rate of deterioration is due to the more 
or less constant sitting of broody hens on the nests, while in the 
latter it was caused by a scarcity of nests. There were no sitters 
present in the latter, but the fact that 8 or 10 hens would lay in the 
same nest daily brought about practically the same condition, and, 
as will be observed from the table, the total loss was even greater in 
the latter instance. 

2. A comparison of the total losses for fertile and infertile eggs 
wiU show that in the former class when sitters were not present the 
loss was 38.6 per cent greater than that in the infertile, and where 
sitters were present the loss was 32.8 per cent greater. The bulk of 
the loss in the two fertile-egg experiments was caused by the devel- 
opment of blood rings and rots, while in the infertile it was due to 
seconds. 

3. The infertile eggs proved to be more resistant to deterioration 
than the fertile when placed in nests for layers with the sitters present. 
The total loss at the packing house for fertiles (sitters present) was 
64.2 per cent and for infertiles under the same conditions only 31.4 
per cent. It must also be remembered that the quality of the infer- 
tile eggs was superior to the fertiles, since the seconds, which com- 
prise the bulk of the loss in this class, are so designated simply be- 
cause they show a slight shrinkage of contents and in some instances 
a little heat. Figures 3 and 4 in Plate III illustrate the difference 
between the fertile and infertile seconds of this experiment. 

The conclusions for this test may be summarized as follows : First, 
irregularity in gathering the eggs from the nests used by the layers 
is one of the ways in which a serious loss in the quality of the egg 
may occur on the farm. Second, infertile eggs are the most resistant 
to this condition. Third, the greatest loss in fertile eggs occurred 
in the test when sitters were not present. The reason for this has been 
explained, and it is quite probable that even in instances when one 
nest was provided for every four or five hens the loss resulting from 
irregularity in gathering the eggs would be about as serious as that 
where sitters are present. 



RESULTS OF THE EXPERIMENTS. 



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RESULTS OF THE EXPEBIMENTS. 27 

D. THE SnTINO HEN EXPERIMENTS. 

The chief value of this experiment lies in the fact that the results 
obtained enable us to state accurately the least time required to 
render a fertile egg unfit for food. 

1. Fertile eggs after being incubated under a sitting hen for 24 
hours developed into what is known to the trade as light floats. 
The only change manifested in infertile eggs under the same conditions 
was a slight shrinkage in the contents, thereby causing the air cell 
to appear larger than that found in the fresh laid egg. 

2. In the 36-hour test it was very apparent that some time between 
24 and 36 hours of incubation the blood commences to assume suffi- 
cient prominence so tliat it can be detected when held before the 
candle. After being allowed to die, the embryo takes on an appear- 
ance as shown in Plate IV, figure 1, where it wiU be seen that the 
blood settles toward the edge of the yolk, forming an irregular 
circle. In infertile eggs, with the exception that the air-ceU is 
necessarily larger, the change is practically the same as that explained 
above in the 24-hour test. 

3. That ir the 48 and 72 hour tests (see Plate IV, fig. 3) the appear- 
ance of the fertile eggs, in relation to the formation of blood, is similar 
to that found after 36 hours except that the development is much 
more marked. In Plate V, figure 1, is shown a living embrj'^o after 
72 hours of incubation, and in Plate VI, figure 1, the same egg after 
life had become extinct. Infertile eggs which have been subjected 
to this amount of incubation are similar in appearance to that shown 
in Plate V, figure 2. They do, however, show an increased amount 
of shrinkage, or enlargement of the air cell, as incubation proceeds. 

The conclusion to be drawn from this investigation is that after 36 
hours of incubation there is a sufficient quantity of blood present in a 
fertile egg when held before the candle to be detected by the naked 
eye. 

It may be noted that there is no table accompanying this experi- 
ment. The photographic representations given in Plates III, IV, V, 
and figures 1 and 2 of Plate VI present the case so forcibly that no 
tabular data are needed. These pictures show conclusively how 
rapidly fertile eggs deteriorate under a sitting hen, and they also 
show the great superiority of infertile eggs under these conditions. 

E. THE CORNCRIB EXPERIMENT. 

The conditions of the two experiments just discussed were, so to 
speak, normal, while those of this experiment and of the succeeding 
ones are abnormal. The object in the former case was to ascertain 
which of the two places was most conducive to good quality in eggs, 
while in the latter case definite knowledge as to where and how the 



28 THE CABE OF THE FABM EGG. 

great mass of bad eggs are produced was sought. If the producer is 
to be educated along these lines, it is desirable that we not only 
determine where eggs keep well, but also that we point out the 
possible conditions that may give rise to a great number of bad eggs. 
Such information may enable him, if he so desires, to eliminate 
certain undesirable conditions and thereby increase the production 
of good marketable eggs. 

From the data in Table 4 we may note the following points: A 
comparison of the losses in clean fertile and infertile eggs kept under 
a comcrib will show that the latter class was more resistant to the 
enyironmental conditions of the experiment. This is particularly 
noticeable in the grades of spots, blood rings, and rots, where the 
infertile egg, on account of its keeping quaUties, could not deteriorate 
because of the development of life within it. It will be remembered 
that spots, blood rings, and rots are a total loss, and in the clean 
fertile eggs 25.1 per cent of the total number were classed under these 
grades, wliile in the clean infertile only 2.4 per cent were discarded for 
like deterioration. As has been mentioned before, the activitv of the 
young cockerels was the cause of a. small per cent of fertility in the 
supposedly infertile eggs. 

A comparison of the seconds in the two classes will show a similar 
condition to that just explained in the "House experiment." 

To sum up briefly, we may say that when kept on the earth under 
the comcrib, clean infertile eggs retained the qualities described in 
eatable eggs better than those which were fertile. 



( 
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RESUtTS OP THE BXPEBIMENTS. 



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30 THE CABE OF THE FABM EGG. 

F. THE WEED-NEST EXPEBIMENT. 

From the data in Table 5 we note: 

1. That of the three classes of eggs with which tests were carried 
on in the weed nests dirty fertile suffered the greatest loss. It is 
noticeable; however, that the difference in loss between clean and 
dirty fertile is very slight. 

2. The development of blood rings and rots in both classes of fertile 
eggs was the main cause of the heavy loss. While it is true that the 
seconds are responsible for a part of this loss, the actual figures for 
the 385 clean fertile eggs would be 81 cents loss for seconds and 
cracked, and a combined loss of $1.23 for spots, blood rings, and rots. 
In the case of the 231 dirty fertile eggs, the figures would be 50 cents 
loss for seconds, and 74 cents for the blood rings and rots, which 
proves that the burden of the loss must be credited to the spoiled 
eggs. 

3. A comparison of the losses at the packing house (see last column 
of the table) gives superiority to the clean infertiles by a margin of 
21.8 per cent, again demonstrating that infertile eggs possess in a much 
higher degree those qualities which tend to make them resistant to 
undesirable keeping conditions. 

The conclusions which may be reached from this experiment are: 
First, that fertile eggs which might be laid in nests in the weeds and 
not discovered for several days can easUy develop into spots, blood 
rings, and rots during the warm weather. Second, that infertile eggs 
under the same conditions do not deteriorate to the extent of fertiles. 
Third, that of all clases, clean infertile were in the best condition 
when candled at the packing house. 



1 



BESULTS OF THE EXPEBIMENTS. 



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32 THE GABE OF THE FAKM EGG. 

O. THE STRAW-STACK EXPERIMENT. 

From the results of this experiment, as set forth in Table 6, we 
may note the following points : 

1. The difference in loss between clean fertile and infertile is 
much less than that of any other experiment, which would indicate 
that t*he conditions of the straw-stack nest were of such a severe 
nature that the infertile eggs were unable to resist it as successfully 
as they did in the other cases. This point is well illustrated by the 
figures in the colunm headed *^Rots/' where it will be noted that 
fully 5 per cent of both classes of eggs were so designated when 
candled at the packing house. Further illustration is found in the 
fact that in both fertile and infertile eggs the number of spots was 
greater than that experienced under any other condition. 

It may also be of interest to note that during the extremely hot 
week of July 1 to 8 eggs that had been in this experiment after being 
candled at the packing house were broken and the albumen found to 
be cooked so hard that it could be cut with a knife without running. 

2. The clean fertile eggs contained 20 blood rings (see candling 
report at packing house) while in the infertiles none were present, 
thereby making the total loss greater than in the infertile eggs. 

3. Even under these severe conditions 24.8 per cent of the infertile 
eggs graded as firsts at the packing house, again demonstrating that 
this class of eggs is more resistant to bad conditions than any other. 
In concluding, we may say that this experiment gave the greatest 
number of spots and rots in infertile eggs. 



BESULTS OF THE EXPERIMENTS. 



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34 THE CABB OF THE FABM EGO. 

H. THE STOLEN-NEST EXPERIMENTS. 

Before discussing the results of these tests, as set forth in Tables 
7, S, and 9, it will be well to state that whenever two or more hens 
would lay in a nest on the same day all but one of the eggs laid were 
removed. This was done to keep the factor constant and not varying 
from day to day. 

That there is a great difference in the quahty of fertile eggs taken 
from a stolen nest just previous to the time the hen starts to sit is 
well brought out in Tables 7 and 8. In Table 7 it will be noted that 
9 out of the 10 eggs were graded as seconds and the remaining 1 as 
a first, whUe in Table 8 there are 9 blood rings and 2 seconds. The 
only logical reason that can be set forth as the probable cause of such 
a variation is that the hen responsible for the eggs in nest 2 was in- 
clined to sit on the eggs for a longer period each day during the time 
she was accumulating the nest of eggs than was the hen of nest 1. 
The fact that both experiments were conducted on practically the 
same days of the month makes the weather conditions identical in 
each case and eliminates the possibility of variations in temperature 
being responsible for the increased deterioration of the eggs in the 
latter nest. In both cases it was accurately determined, by breaking 
the eggs directly after candling, that those candled as seconds were 
fertile, since they showed similar development to that shown in Plate 
III, figure 3. The development had, of course, proceeded further in 
some instances than in others, but in every case it was of sufficient 
prominence to positively identify the egg as fertile. 

Turning to Table 9, which is a condensed report of the detailed 
records of the 12 stolen nests, we may note (1) that out of the total of 
88 eggs only 7.9 per cent could be classed as firsts when removed from 
the nest; (2) that slightly over one-half of the number had developed 
into seconds, 38.6 per cent being a total loss, and (3) that there was a 
total money loss of 60 per cent of the original ^value of the eggs. Such 
results as these, when we consider that the eggs had not been set 
upon steadily, as is the case in many nests of eggs which are found 
on the farm, are sufficiently convincing to prove that the eggs procured 
from such sources can easily be responsible for a part of the great loss 
now borne by the producer. 



BESULTS OF THE EXPERIMENTS. 



35 



Table 7. — Record of stolen nest No. 1, located in weeds. 



Dates visited. 



May 12 
Kay 13 
May 14 
Hay 15 
Hay 16 
Hay 17 
Hay 18 
Hay 19 
Hay 20 
Hay 21 
Hay 22 
Hay 23 



Nomber 
of bens 
laying 
in nest. 



1 
1 
1 
2 
1 
1 
2 
3 
1 

1 




Hen 
sitting. 



No.. 

No. 

No.. 

No.. 

No.. 

No.. 

No.. 

No.. 

No.. 

No. 

No. 

Yes. 



Weather conditions. 



Rain. 



Indiet. 
0.00 
T.> 
.22 
.00 
.00 
.00 
.00 
.00 
.00 
.58 
.00 
.00 



Sky. 



Clear... 

Pt.cl». 

. . .do 

...do... 
...do... 

Clear.. . 

Pt. cl. . 
...do... 
...do... 
. ..do. . . 
...do.. . 

Clear... 



Tempera- 
ture. 



Hax. 



F. 

87 

87 

84 

81 

90 

91 

93 

80 

75 

66 

61 

86 



Min. 



44 

57 
65 
52 
65 
64 
72 
70 
52 
50 
41 
62 



Date 
candled. 



May 24. 
...do... 
...do. . . 
...do.. . 
...do... 
...do.. . 
...do... 
...do... 
...do... 
...do.. . 
...do... 
...do... 



Orade 
of egg. 



iSeoond. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 

First. 



» Trace. 
Note.— Second showed 24-hour development. 



» Part cloudy. 



Table 8. — Record of stolen nest No. 2y located in woodpile. 





Number 
of hens 
laying 
in nest. 


Hen 

sitting. 


Weather conditions. 


Date 
candled. 




Dates visited. 


Rain. 


Sky. 


TemiMra- 
ture. 


Grade 
of egg. 




Max. 


Min. 




May 12 


1 








I'o 

No.... 
No.... 
No.... 
No.... 
No.... 
No.... 
No.... 
No.... 
No.... 
No.... 

No.... 
No.... 
No.... 
Yee... 


Indus. 
0.00 

T.i 
.22 
.00 
.00 
.00 


Clear.... 

Pt.cl.>.. 
...do.. . . 

...do 

...do 

CieftT 


87 

87 
84 
81 
90 
91 
93 
89 
75 
66 
61 

85 
96 
95 
94 


44 

57 
65 
52 
65 
64 
72 
70 
52 
50 
41 

62 
55 


May 26.. 

...do.... 

...do 

...do 

...do 

...do. . . . 
...do.. . . 

...do 

...do 

...do 

...do.... 

...do.... 
do 


Blood 


Hay 13 


ring 
Do. 


Hay 14 -. 


Do. 


Hay 15 




Hay 16 


Do. 


Hay 17 


Do. 


Hay 18 


.00 Pt.el.r. 


Do. 


Hay 19 


.00 
.00 
.58 


...do 

...do 

-do 


Do. 


Hay 20 




Hay 21 


Second. 


"May ?? . . . 


.00 '---do 


Blood 


May 23 


.00 
.00 
.00 


aear.... 
...do 

do 


ring. 
Do. 


Hay 24 




May 25 


67 ...do.... 
69 - do 


Second. 


Hay 26 


.00 l--do 

















» Trace. 
Note.— Second showed 24-hour development. 



Part cloudy. 



Table 9. — Condensed report of stolen nests. 





Total 
egSB. 


Results of candling. 


• 

Origi- 
nal 
value 

cents 

per 

doxen. 






Total number of 
neslB. 


Firsts. 


Seconds. 


Blood rings. 


Rots. 


Loss. 


12 


88 


Num- 
ber. 
7 


Per 

cent. 

7.9 


Num- 
ber. 
47 


Per 
cent. 
53.4 


Num- 
ber. 
27 


Per 
cent. 
30.7 


Num- 
ber. 
7 


Per 

cent. 

7.9 


DoOart. 
1.10 


DoUart. 
0.66 


Peret. 
60 







36 THE CABE OF THE FABM EGO. 

COMPARISON OF CLEAN FBRTHA BGOS UNDER SEVEN DIFFERENT 

CONDITIONS. 

We have already discussed the results of the seven different experi- 
ments incorporated in Table 10, and it will now be of interest to com- 
pare collectively the total number of clean fertile eggs in each of them. 
Before doing so, however, it is well to call attention to the fact that 
the date in the table on which the tests with clean fertile eggs began 
is with one exception given as April 24, while in the condensed tables 
referring to the separate experiments it is given in some instances as 
June 10 and in others as June 17. This apparent contradiction is 
owing to the fact that the tests with infertile eggs did not start until 
the latter dates, and if we are to compare the results of experiments 
with these two classes of eggs, it is obvious that the work in each case 
must start and end on identical dates. 

From the data in Table 10 the following points will be noted: 

1. A comparison of the number and per cent of blood rings and 
rots which were present in the eggs of the different experiments when 
candled at the packing house will show that those kept in the cave 
were the only ones that did not suffer a heavy loss through these two 
grades. In the cave eggs the loss from this source was only 0.5 per 
cent, while in the remaining experiments it varies from 8.8 per cent 
for straw stack to 55.1 per cent in nests for layers. 

2. The conditions in the straw-stack experiment gave rise to the 
greatest number of spots. By referring to Table 11, it can be seen 
that this also held good in the case of infertile eggs. 

3. By comparing the total per cent of loss of each experiment it 
will be seen at a glance that the irregular gathering of the eggs (nests 
for layers test) was the cause of the greatest loss both at the farm 
and packing house. On the other hand one can see immediately 
that, excepting the cave experiment, the various conditions imder 
which the tests were made are responsible for a large part of the bad 
eggs which we find on the market to-day. 

4. In all experiments except the cave the total depreciation in the 
quality of clean fertile eggs is of enough importance to justify the 
statement that high-quality eggs can not be produced under any of 
these conditions. The best place to keep eggs, other than the cave, 
was found in the parlor of the dwelling house, and even here we note 
a total loss of one- third of the value of the eggs when candled at the 
packing house. This result must obviously eliminate such a location 
as a suitable place to keep fertile eggs during the warm weather, which 
leaves the cave or dry, cool cellar as the only alternative. 



COMPABISON OF CLEAN FEBTILE EGOS. 



37 



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38 THE CABE OF THE FABM EGG. 

COMPARISON OF CLEAN INFERTILB BOOS UNDER SEC DIFFERENT 

CONDITIONS. 

It may be noted from the data given in Table 11 concerning the 
clean infertile eggs in the various experiments : First, that eggs held in 
the cave gave the highest percentage of firsts at the farm and packing 
house, and that the eggs kept in the parlor of the dwelling house were 
second best. Second, instead of the greatest deterioration occurring 
in the eggs placed in the nests for layers, as was the case with fertile 
eggs, we find that those of the straw stack suffered the heaviest loss. 
Third, that the straw-stack condition was the most conducive to the 
production of spots and rots in infertile eggs. Fourth, excepting the 
cyclone cave, the final losses under all the other different conditions 
plainly show that they are not conducive to good quality in ^gs. 
With the exception of the house experiment such results would 
naturally be expected. 



COMPABISOK OF CLEAN INFEBTIL£ EGGS. 



39 



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THE CABE OF THE FABH I 



From the data in Table 12 and the graphic representation in text 
figure 1 we note: 

1. That in all three candlings the loss in fertile eggs is nearly twice 
that of the infertHe. This point is of the utmost importance to the 
producer, since it demonstrates beyond a doubt that by removing 
the male birds as soon as the hatching season is over, which should 
be about the middle of May, the quality and value of the subsequent 
eggs, regardless of where they are kept, is increased very materially. 

2. The increased loss in fertile eggs is due mainly to the develop- 
ment of blood rings and rots, which, as has been shown in the pre- 
vious discussion, can easily occur even when the eggs receive good 
care on the farm. The fact that they are fertile makes them subject 
to rapid deterioration of such a nature as to render them unfit for 
consumption. 

3. By referring to figure 1 it will be seen that practically two- 
thirds of the total loss in fertile and infertile e^s occurred on the 



Fia. I.— Stiovlns percent alloss in lertOeaad Infertile eggs rrDmbim to market. [See Table 12.) 

farm, the remaining loss taking place in town and during transporta- 
tion from town to packing house. It is highly probable that if the 
e^s had all been firsts when leaving the farm the above loss would 
have been materially lessened. The important point to be brought 
out, however, is that the haphazard methods followed in the produc- 
tion and care of eggs on the farm are the principal factors which must 
be eliminated if the quality of the commercial egg is to be improved. 
True, there is room for improvement in the methods of handling and 
transportation after the egg leaves the farm, but, as brought out in 
Table 1 (p. 22), the only depreciation occurring during transit in 
clean infertile eggs kept jn the cyclone cave was a slight shrink in the 
contents of a part of them, thereby making it necessary to class them 
as seconds. 



C0MPABI80N OF LOSSES IN BOOS. 



41 



.O lO 






f-liO MS CI 

S3 ^ ^ 



306 ^ 



^9 s ;:: 



o 



oisa 



;lia 



is. 









3gsl 



o*5r?:g 



§ S S 



^ !fi V 

» S s:i 

•« a^ vk a^ 1^ 4^ 



o 
8 



3 

o 



a 

OQ 



t 
I 



•3 

i 

CO 









• • • ■ 






a*- S8 8 






•HIO CO N 

9 * • ■ 



I' 



.;i^2 



ga g ^ 






ua^ o to 



P=^ 



;^8 S) » 



1^? 



+ 

o 



i i 



•1^ 



O ^ ©•-« »H o 






lOOO Ok «D 

■ « • • 

MM C« CO 



ps a 



88 2 8 






3$ !i ? 






g§ § 






•or« CO o 



lis S IS 5 



»o ^ M 

•H i^ t* 

C4 <o 2» 



I 



9 



I 

"a 

I 

o 



% 



S 

I 



I 



1 



O 












•8 



000 

T> "O "D 



O . 






1 I 



42 THE GABE OF THE FABM £00. 

RELATION OF TEMPERATURE TO DETERIORATION IN EGGS. 

In the condensed reports of the different experiments it has only 
been possible to note the total depreciation for the season. There- 
fore it will be of interest to here note the deterioration in fertile and 
infertile eggs of various ages during moderately cool and extremely 
hot weather. Tables 13, 14, and 15 are detailed reports of 7-day 
experiments conducted in the parlor of the dwelling house, and the 
figures contained in them are the results of the first candling, which 
represents the loss at the farm. Figures 2 and 3 are thermograph 
reports of the temperature and humidity of the room during the 
time the above tests were made. The experiments started and ended 
on Saturday, as will be noted by referring to the thermograph records, 
where it will be seen that directly under Saturday there is a break in 
the line representing the temperature. This, of course, is occasioned 
by beginning and ending the record on the above day. 

From figure 2, and the data in Table 13, which records the results 
of keeping fertile eggs in moderately cool weather, we note: 

1. That the range of temperature for the seven days was between 
63 and 88^ F. 2. When subjected to the above range of temperatiu-e 
there was no loss in fertile eggs from one to six days old. 3. That in 
fertile eggs seven days old one out of six had deteriorated so as to 
become a second, which meant a decrease in quality of 16.7 per cent. 
The actual money loss, however, resulting from the above shrinkage 
in quality is but one-half a cent, which is not serious enough to be of 
significance. 4. That fresh fertile eggs placed in an unheated room 
of the dwelling house, the maximmn daily temperature of which is 
88° F., or imder, will, if marketed frequently, be in sufiiciently good 
condition to grade as firsts or full fresh eggs. There is a possibility 
that they would be in good condition at the expiration of seven days, 
but it is wiser to dispose of them at least twice a week. 

Tmrning to Tables 14 and 15, where is given the depreciation dur- 
ing extremely hot weather, we find that after 24 hours 40 per cent of 
the fertile and 20 per cent of the infertile eggs had developed into 
seconds. At the age of four days 40 per cent of the fertile eggs are 
a total loss and on the fifth day 100 per cent. In the infertile eggs 
(Table 15) the rate of deterioration is not so great, but after the 
fourth day 100 per cent o( the eggs are seconds. At the end of seven 
days the infertile eggs have a market value of 6(T per cent of their 
original value, while the fertile eggs under the same conditions are a 
total loss. 

The conchisions which may be drawn from the results of these 
three experiments are: First, that the quality of fertile and infertile 
eggs retained in a room of the dwelling house does not change to any 
appreciable extent during a period of from four to five days when the 



■ BfilATtOK OF lEM&EEATUBB TO DETEBIOBATION. 



43 



maximum temperature is SS° F., or under. Second, during extremely 
hot weather, when the daily maximum temperature is 100° F., or 
over, both fertile and infertile e^s start to deteriorate during the 
first 24 hours. The depreciation in fertiles Is so rapid that after the 
fourth day they are a total loss, while in the infertiles, owing to the 
absence of fertilization, the loss is much less. 

Table 13.—Detmoration in/trtiU egg* kept in dwelling hotue during ■moderaUl}/ cool 



Nam- 
b«of 
eggi. 


Ap. 


RtHulUDlnodUns. 


FlnU. 


Bmnuli. 


Cracked. 


Ltttken. 


Spo.. 


Blood lings. 


Hots. 


1;;;;::; 

!::::::: 

t'.'.'.'.'.'.'. 


1 




IW 




ffo. 


P. a. 

19.7 




P.d. 







ffb. 


P.d, 


I 


'''1 

I 





p.d. 





r.d. 



I 


T(.(^.4a 




" 


„. 


' 


2.* 











o; 


° 


» 


" 


" 


' 



Tablb 14.- 


DeUriortUion in 


JfrHUegg»tep 


in duelling houte during very hot iDtather. 






ResolMotouidling. 




Are. 






















Finn. 


SeooDds. 


Cracked. 


Lraken. 


Spota. 


Blood rings. 


Ro,. 


^. 


fCo 


Prf 


Vo 


Pa 


K« 


P.et. 
























































«.U 














! 


s 















I 


! 




° 











!! 




100.0 

100.0 





s 


ToUI.36 




B 


14.3 13 


J7.J 





0| 


0| 


» 


" 


4S.S 


» 


• 



44 THB CASE OF THE PABM EOO. 

T&BLB 15.— Z)efanoFalton m infertile egg* lept in dweUinff houte during vay hot weather. 



berol 


AH". 








B,«.l«»,«ndling. 






















Flreto. 


s«™d,. 


erected. 


L«ki«. Bpou. 


.y^r^ 


Rote. 




Dm. 


Tfe. 


so.o 

100.0 





At*. 


So. 


P.cf. 


JTb. 



P.ct.\ So. \p.a. 


So. 


P.tl. 


Sn. P.d. 








40,0 


I 


looio 






















TduI.U 




U 


«" 


30 


ST. 2 


" 


« 











» 


" 


-0 



Fu. S.— ThenoDgraph nxonl ibowtnf tenywrature In parinr of dwdllug hau» lor 0D« w«A dnrine h< 



""fffmrmwf 


''?^^T;"'-*rT ^--rr- 


I^-S -, ^ ^ 5 J 5 


J 1 7\ - 


;^_ A ^1 \t \ 


t ^,/^^j ^;z^ 












^^ ^-I ^I 




r ^^--l '-\ 


Z ^""5 A ,^\ ^' 


i J b' ^ 




^,L 






hire; lower reprwentahumidlty. On Wednesday, Ju 
iDreed ofl the mnrdlDE sheet, as It It deigned to im 

**r MHVMK MBMMV THCnHK M 




Z~-~-Xzt - -"' "^ " 




» '^i-p - 




~ ^^ ..^^\ ^^\ 


c^^l ^^z ^^Z~ 


Z ■^^ ^ 7 ^-^ 




Z-- ^ bi 


' 


Z '■I /:v^ s; ' 


Tj^l _il 


« / 3 Z--"Z A ,- 


s ^ Z^ ,^:s" 


«- r/ ^'^- 




u 


^^ ^T- < 




r 



cmperature and humlditv records token Horn Ihermograph iisad la the hotus eipRl 
week June M lo July 1, 1911. Upper Uoe itpttBento temperature; lower, hotnldl^. 



RELATION OF TEMPEBATUBE TO DETEEIORATION. 



[a. 0— Tcmpentun and humjdlly reconla taken bom thermoKTsph tiwd In o 
week June24 toJuIjl, IMl, Upper lino reprasenla tempeiatura; low 



-_ , itor, July 1, and end! at 10a.m. WtdiKS- 

_, ., .. when tbe tnin WB3 in motion, and the light smooth line that tha 

(rawere held In the country a lore (rom 6 o'clock Saturday, July l.unta about 10 o'clock Monday, July 
3, ISll. Sgsi and thennogisph were In open stock car. Note ^it e h temperature at 2 o clock Ttifsday, 

SDMHARY. 

■ This paper constitutes a general study from a practical staudpoint 
of the deterioration occurring in the various classes of fertile and 
infertile eggs when kept on the farm under different environmental 
conditions. The data on which this study is based are the results of 
extensive experimental egg work carried on in the State of Kansas. 
The chief results of these tests are summarized in the following 
paragraphs: 

1. E^ kept in the cyclone cave proved much better in quality 
than those kept under other conditions. 



46 THE CABB OF THE FARM EGG. 

2. Taking the season as a whole, an unhealed room in a dwelling 
house is not conducive to good quality in eggs. 

3. During the hot summer months the conditions surrounding the 
weed nest, the nest in the straw stack, or imder the comcrib, and 
the stolen nest, as well as the keeping of eggs in the house, favor the 
production of spots, blood rings, and rots. 

4. The greatest deterioration in fertile eggs occurred in the experi- 
ments which included a certain amount of natural incubation, namely, 
in the nests for layers and the.stolen-nest experiments. 

5. The straw-stack experiment gave the greatest number of spots, 
both in fertile and infertile eggs, and also the highest percentage of 
rots in the latter class of eggs. It was the only test in which a large 
number of infertile eggs deteriorated to such an extent as to be unfit 
for food. 

6. In fertile eggs the development of the embryo after 24 hours of 
incubation was of sufficient proportion to be recognized when held 
before the candle, and at the expiration of 36 hours the presence of 
blood was easily detected. In infertile eggs under the same condi- 
tions a slight shrinkage of the contents was the only change which 
could be recognized by the eye. 

7. Infertile eggs, regardless of where they may be kept, are much 
more resistant to deterioration than fertile. 

8. Two-thirds of the total loss in fertile and infertile eggs takes 
place on the farm. The basic factors responsible for this condition 
are the haphazard methods of poultry management on the farm. 

9. If eggs are fresh when delivered to the buyer it is impossible, 
with the present methods of transportation, for them to reach the 
packing house without showing a slight deterioration in quality. 
The data at Jiand (see Table 1) would indicate that this loss is about 
12 per cent of the original value of the eggs. 

10. The results of all the experimental work point to the fact that 
the production of the infertile egg is the greatest asset in the attempt 
to produce high-quality market eggs during hot weather. 

11. The authors beUeve that if the five simple rules given below are 
followed by egg producers generally a high quality of product will 
be assured and a very large part prevented of the loss now expe- 
rienced in the value of the country's egg production: 

Give the hens clean nests. 
Gather eggs at least once daily. 
Keep eggs in a cool, dry place. 
Market eggs at least twice a week. 

Eall or sell all mature male birds as soon as the hatching season 
closes. 



Fki. 1.— Normal Fresh Eoa. FiQ. 2.— Fresh Eqo Showinq Blood Clot. 



Fig. 4.— Infebtile Egg After 7 Days 



Fig. 3.-EGQ Showing Mold Spot. fig. 4. -Ego Showing Plain Spot. 



APPENDIX. 

As a sample of the way in which the complete data of the various 

experiments in this bulletin were placed on record, we append the 

details of the cyclone-cave experiment as carried out throughout the 

season, from April 24 to August 26, 1911. A condensed report of 

this experiment has previously been given as Table 2, on page 25. 

It is considered unnecessary to publish the complete records of the 

other experiments. 

47 



48 



THE CABE OF THE FABM EGG. 



Detailed record of the 



6 



M 



20 



21 



40 



41 



42 



67 



68 



50 



03 



64 



65 



87 



80 



00 



01 



02 



100 



110 



111 



Kind of eg^ 



FertUe.. 



.do. 



Washed fortlle. 



Dirty fortlle. 



FertUe. 



Dirty fortile. 



Washed fertile. 



Fertile. 



Dirty fertile. 



Washed fertile. 



FertUe. 



Dirty fertUe. 



Washed fertUe. 



Infertile. 



Washed inHartUe. 



Dirty InfertUe. 



FertUe. 



Dirty fertUe. 



Washed fertUe. 



InfertUe. 



Dirty, InfertUe. 



Washed, infertUe. 



3 



3 



3 



3 



3 



3 



3 



3 



3 



* 



30 



36 



18 



18 



42 



21 



21 



42 



21 



21 



30 



15 



15 



35 



21 



21 



35 



21 



21 



35 



21 



21 



Len^of 
expenment. 



Weather and 
temperatoxe.* 



{ 



Apr. 24-30.. 

Apr. 30- 
MayO. 



Tables 1, 2. 



}Table8l,2,6... 



.do. 



.do. 



.do. 



May 6-13. 



.do. 



.do. 



/Tables 2, 7; reo- 
\ ord7. 

do 



.do. 



.do. 



Mayl3-20...r»W«2.8J"»- 



\ ordia 



.do. 



.do. 



.do. 



.do. 



May 22-27... {T*5J-j^»'»J«o- 



.do. 



.do. 



r 



ay 27- 
June3. 



.do. 



.do. 



.do. 



.do. 



.do. 



June 3-10.... 



.do. 



.do. 



.do. 



.do. 



Tables 2, 3, 10; 
record 16. 



.do. 



On arrival in town 

Before leaving town. 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at pacUng house. 

On arrivalin town 

Before leavinc town 

Arrival at packing house. . 
On arrivalin town 

IBefwe leaving town 
Arrival at packing house. 
On arrival in town 
Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing bouse. 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at packing house.. 

On arrival in town 

Before leaving town. 

Arrival at pacing house. . 

On arrivalin town 

Before leaving town 

Arrival at packing house . . 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival In town 

Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at pacnng house. . 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at packing house . . 

On arrivalin town 

Before leaving town 

Arrival at r^M"g house.. 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at packing house . . 

1 A oomparisoii of the figures under column headed " Total eggs" with those under oolnnm "Total eggs 
candled ** wiU often show a variation. This variation is due to eggs becoming broken or lost. ^^ 

s The tables and records referred to in this column are not those in the present bulletin. They are ptft 
of the original data on file in connection with the complete records of these experiments. 

* Five eggs broken. 



.do. 



.do. 



.do. 



.do. 



/Tables 3. 11; reo- 
\ ordlO. 

do 



.do. 



When candled. 



46 



eydont-txivt txperiment. 



M 


M3 





^° 


1 


la 








j; 


J 


J 




3.9 


35 


11 


31 


ti.3 


2 




1 


2.9 


















M 




10 


eg. 3 





























34 


11. s 




UO.D 









o' 






















31 


c 


ao 


100.0 

































IS 


too 































ai 


100.0 



































10O.O 

























a 


a 


31 





IB 


M.a 




1B.8 



























la 


U.S 



50 



THE GABE OF THE FABM EGG. 



Detailed record of the cydone- 



112 

lis 

114 
131 
132 
142 
143 
157 

IfiS 
159 

lao 



181 



182 



183 



203 



204 



206 



206 



223 



224 



226 



226 



KJndofeg0i. 



Fsrtile.... 



Dirty, fertile.... 
Washed, fertile. 



Fertile. 



Washed, fertile. 



InfertUe. 



Washed, InferUle. 



Fertile. 



Washed, fertile. 



InferUle. 



Washed, infertUe. 



180 Fertile.... 



Washed, fertile. 



Infertile. 



Washed, Infertile. 



Fertile. 



Washed, fertile. 



Infertile. 



Washed, inXertlle. 



Fertile. 



Washed, fertile. 



Infertile. 



Washed, infertile. 



Fertile. 






I 



3 



3 






35 
21 
21 
35 
21 
35 
21 
35 
21 
35 
21 
35 
21 
35 
21 
35 
21 
35 
21 
85 
21 
35 
21 
35 



Length of 
xpenment. 



expei 



June 3-10 . 

do 

do 

June 10-17. 

do 

do 



June 17-24.. 

I • • • ■ \XV« • • « • • < 

do 



( 



•""• V • • • • * 

June 24- 
July 1. 



do 

do 

do 

July 1-8.... 

do 

do 

.....do 

July 8-15... 

do 

do 

do 

July 15-22.. 



Weather and 
temperature. 



When candied. 



/Tables 3, 11; rec- 
\ ord 19. 



.do... 



/Tables 3,12; reo- 
\ ord 22. 

■ • • « • %»V* •«••>••>■■ 



.do. 



.do. 



/Tables 3,13; reo- 
\ ord 25. 



.do. 



Tables 3, 4, 14; 
record 28. 



.do. 



.do. 



.do. 



/Tables 4,15; reo- 
\ ord 31. 



.do. 



.do. 



.do. 



/Tables 4, 16; reo- 
\ ord 34. 



.do. 



.do. 



.do. 



/Tables 4, 17; reo- 
\ ord 37. 



On arrival in town 

Before leaving town 

Arrival at packing bouse . 

On arrival In town 

Bdbre leaving town 

Arrival at r»^Mng house. 

On arrival in town 

Before leaving town. 

.Arrival at parking hoosa. 

On arrival in town 

Before leaving town 

Arrival at packing bouse. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house . 

On arrival u town 

Befwe leaving town 

Arrival at pocking house. 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival In town 

Before leaving town 

Arrival at packing house . 

On arrival In town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at nnuing house . 

On arrival in town 

Before leaving town 

Arrival at packing house 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrivalln town 

Before leaving town 

Arrival at packing house. 

On arrival In town 

Before leaving town 

Arrival at packing house . 

On arrival in town 

Before leaving town. 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at pacUng house^ 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at paoUng house. . 

On arrival in town 

Before leaving town 

Arrival at packing house. . 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at pacldng house. • 
On arrival in town 



Before leaving town 

Arrival at pocking boose. • 



> One egg broken. 



cave experiment — Continued. 



-; 


IS 


£ 


sio 


4 




; 






3 


I 


19 


1 


It 


is 


B7:i 


1 


100.0 
4.B 


« 


Is 




























31 


33.3 
35.3 


31 
































S.S 


30 


86^7 





























35 






37.1 


30 


S7.1 




6.7 



















3S 


833 


31 


lOCLO 




















•0 














ao 


W.1 

38.1 


















! 


I 





I 


31 


etl 
































3S 






83.3 




11.4 




i7 





















17,1 




l&i 




».! 

























41.3 




K.i 






























31 




u 


W.a 


3 


».S 

























31 


9.B 


s 


|i 


8 


38.1 

























31 


w 












1! 


























37 


77^1 


e 



























35 


21« 


31 


loao 





o' 







a 

















31 





31 


i«ao 






























31 





IB 


9as 






























31 




33 


»4.1 






























34 




S3 


ftll 


1 


3.9 




2.9 





















H 


G.S 


37 




e 


17.8 




3.3 





















H 


30.e 



52 



THB CABE OF THE FABM BOO. 

I 

Detailed record of the cyclone^ 



o 



I 



244 



346 



246 



263 



264 



206 



266 



283 



284 



286 



286 



803 



a04 



306 



306 



823 



824 



826 



826 



843 



844 



846 



846 



Kind of es^ 



Washed, fertile. 



Infertile. 



Washed, infertile. 



Fertile. 



Washed, fertile. 



Infertile 



Washed, infertile. 



FerUle. 



Washed, fertile 



Infertile. 



Washed, infertile. 



FertUe. 



Washed, fertile. 



Infertile. 



Washed, infertile. 



Fertile. 



Washed, fertile. 



Infertile. 



Washed, infertile. 



Fertile. 



Washed, fertile. 



Infertile. 



Washed, infertile. 






d 

^ 



3 
5 
3 
6 
3 
5 
3 



I 



5 
3 
5 
3 
5 
3 
5 
3 



1 



Length < 
ezpenmei 



hof 
int. 



35 



21 
35 
21 
35 
3 I 21 
5 ' 35 
3 21 



35 
21 
35 
21 
35 
21 
35 
21 



{ 



July 29- 
Aug. 5. 



do 

do 

do 

Aug. 5-12.. 

do 

do 

do 

Aug. 12-19. 

do...., 

do 

do , 

Aug. 7<W2f>. 

....do 

....do 



Weather and 
temperature. 



/Tables 4, 17; reo- 
\ ord37. 



Whencandlad. 




/Tables 4, 5, 19; 
\ record 43. 

do 



.do 



.do 



/Tables 5, 20; rec- 
\ ord46. 

do 



.do 
do 



'/Tables 5, 21; rec- 
X ord49. 



.do 



.do 



.do 



/Tables 5, 22; reo- 
it ord52. 



.do 



.do 



On aril val in town 

Before leaving town 

Arrival at packing house. 

On arrlvalln town 

Before leaving town 

Anival at packing house. 

On arrival in town 

Befcwe leaving town 

Arrival at packing house. 

On arrivalin town 

Before leaving town 

Arrival at packing house. 

On arrival m town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house . 

On arrival in town. 

Before leaving town. 

Arrival at packing house. 

On arrival In town 

Before leaving town. 

.\rrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrivalin town 

Bef(»« leaving town 

Arrival at packing house . 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at pamng house . 

On arrival in town 

Before leaving town 

Arrival at packing house. 

On arrival in town 

Before leaving town 

Arrival at paodng bouse . 
On arrival in town 



Before leaving town 

Arrival at packing house. 

On arrivalin town 

Before leaving town 

Arrival at packing house. 

On arrivalin town 

Before leaving town 

Arrival at packing house. 



> One egg brokBii. 



APPENDIX. 



53 



cave experiment — Continued. 











Results of candling. 


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21 


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21 


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19 


90.5 


2 


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21 


9.6 




35 


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85 







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35 







34 


97.1 








1 


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21 







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29 


82.9 


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35 


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21 


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21 







21 


100.0 






































21 







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71.4 


5 


23.8 














1 


4.8 














21 


28.6 




35 


100.0 






































36 







35 


100.0 






































36 







31 


88.6 


4 


11.4 
































35 


11.4 




20 


05.2 


1 


4.8 
































21 


4.8 




20 


95.2 


1 


4.8 
































21 


4.8 




18 


85.7 


3 


14.3 
































21 


14.3 




25 


73.5 


7 


20.6 


2 


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34 


26.5 


0) 


25 


73.5 


7 


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2 


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19 


55.9 


12 


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18 


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2 


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20 


10.0 


0) 


18 


90.0 


2 


10.0 


2 





























20 


10.0 




13 


65.0 


6 


30.0 


5.0 


























20 


35.0 




34 


97.1 


1 


2.9 
































35 


2.9 




34 


97.1 


1 


2.9 
































35 


2.9 




20 


67.1 


15 


42.9 
































35 


42.9 




18 


85.7 


3 


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21 


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18 


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3 


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21 


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12 


57.1 


9 


42.9 
































21 


42.9 




31 


88.6 


2 


5.7 


2 


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35 


11.4 




30 


85.7 


3 


8.6 


2 


5.7 


























35 


14.3 




25 


71.4 


7 


20.0 


3 


8.6 


























35 


28.6 




20 


95.2 


1 


4.8 
































21 


4.8 




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21 


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35 


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35 







35 


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35 







33 


94.3 


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21 







21 


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21 


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21 







26 


74.3 


9 


25.7 
































35 


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68.6 


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35 


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18 


51.4 


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35 


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21 


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20 


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17 


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20 


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18 


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1 


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20 


10.0 




35 


100.0 





• 
































36 







35 


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36 







35 


100.0 






































36 







20 


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1 


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21 


4.8 




20 


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21 


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21 


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21 








o 



\ <rW^' DEPARTMENT OF AGRICUL'e^E. * 



BUREAU OP ANIMAL INDUSTRY.— Bollbtin 16!* \ t 



A STUDY OF THE BACTERIA WHICH 
SURVIVE PASTEURIZATION. 



S. HENRY AYERS, 

Bacteriologisl., 



WILLIAM T. JOHNSON. Jr., 

Scienlifie Assistant, Dairy Division. 



WASHINGTON; 
GOVERMMENT PRINTING OFFICE. 



THE BUREAU OF ANIMAL INDUSTRY. 



CkUf: A. D. Melvin. 

AnistarU Chief: A. M. Farrinoton. 

Chief Clerk: Charles G. Carroll. 

AniTnal Husbandry Division: George M. Rommel, chief. 

Biochemic Division: M. Dorset, chief. 

Dairy Division: B. H. Rawl, chief. 

Field Inspection Division: R. A. Ramsay, chief. 

Meat Inspection Division: R. P. Steddom, chief. 

Pathological Division: John R. Mohler, chief. 

Quarantine Division: Richard W. Hickman, chief. 

Zoological Division: 6. H. Ransom, chief. 

Experiment Station: £. C. Schroeder, superintendent. 

Editor: James M. Pickens. 

DAIRY DIVISION. 

B. H. Rawl, chief. 

Helmer Rabild, in charge of Dairy Farming Investigations. 

S. C. Thompson, in charge of Dairy Manufacturing Investigations, 

L. A. Rogers, in charge of Research Laboratories. 

Ernest Kelly, in charge of Market Milk Investigations. 

Robert McAdam, in charge of Renovated Butter Inspection. 

2 



ADDITIONAL COPIES of this pablloatlon 
'Ti. may be procured from tlia SupSBmTEND- 
XNT or DocuMXMis, Ctovemment Printing 
Office, Washington, D. C, at 10 cents per copy 



LETTER OF TRANSMITTAL. 



U. S. Department op Agriculture, 

Bureau of Animal Industry, 
Washington, D, C, October 7, 191Z. 

Sib: I have the honor to transmit herewith for publication in the 

bulletin series of this bureau a manuscript entitled ''A Study of the 

Bacteria Which Survive Pasteurization," by Messrs. S. Henry Ayers 

and William T. Johnson, jr., of the Dairy Division. 

Respectfully, 

A. D. Melvin, 

Chief of Bureau. 
Hon. James Wilson, 

Secretary of Agriculture. 

3 



CONTENTS. 



Fa«e. 

Intixxiuction 9 

Objects of this investigation 10 

Methods 11 

Temperatures used throughout the country 12 

Bacterial reductions by laboratory pasteurization, using the *' holder '' process . . 13 

Bacterial reductions at 60° C. (140° F.) and 65.6° C. (150° F. ) 13 

Bacterial reductions at 62.8° C. (145° F.) 15 

The control of pasteurization 16 

Effect of long heating on bacteria in milk 17 

Three hours* pasteurization 17 

Six houre' pasteurization 18 

Effect of sudden cooling on the bacteria in pasteurized milk 20 

Groups of bacteria which survive pasteurization 21 

Grades of milk studied 21 

'Methods 21 

The bacterial groups in grade A milk before and after pasteurization for 

30 minutes at 62.8° C. (145° F.) 24 

The bacterial groups in grade A milk before and after pasteurization for 

30 minutes at 71.1° C. (160° F.) 25 

The bacterial groups in grade B milk before and after pasteurization for 

30 minutes at 62.8° C. (145° F.) 25 

The bacterial groups in grade C milk before and after pasteurization for 

30 minutes at 62.8° C. (145° F.) 26 

The bacterial groups in milk pasteurized at high temperatures 27 

The activity of bacteria of the various groups isolated from raw and pasteurized 
milk measured by their ability to produce changes in litmus milk after dif- 
ferent lengths of incubation 28 

Grade A milk before and after pasteurization for 30 minutes at 62.8° C. 

(145° F.) 28 

Grade A milk before and after pasteurization for 30 minutes at 71.1° 0. 

(160° F) 30 

Grade B milk before and after pasteurization for 30 minutes at 62.8° C 

(145° F.) .^ 31 

Grade C milk before and after pasteurization for 30 minutes at 62.8° C. 

(145° F.) 32 

Comparison of the percentage of acid-forming bacteria in raw and pasteiu-ized 

milk 33 

Comparison of the percentage of peptonizing bacteria in raw and pasteurized 

milk 34 

Average percentages of the bacterial groups of raw milk which survive pasteuri- 
zation - 34 

5 



CONTENTS, 



The effect of pasteurization on the number of bacteria of dififerent groups in 

milk ^ 35 

The bacterial development in milk pasteurized in the laboratory and held at 

different temperatures 37 

Qualitative study of the groups of bacteria which survive pasteurization 43 

The acid-forming group of bacteria 43 

The inert group of bacteria 45 

The alkali-forming group of bacteria 45 

The peptonizing group of bacteria 47 

The gas-arming bacteria 47 

Thermal death points of bacteria which survive pasteurization 51 

The possible use in pasteurization of acid-forming bacteria of high thermal 

death point 52 

Qualitative study of the complete bacterial flora of one sample of pasteurized 

milk 53 

Summary 58 

Conclusions 61 

Appendix. Tables 65 



ILLUSTRATIONS. 



Pftge. 

Figure 1. Bacterial reduction during pasteiu'ization for three hours at 54.4^ 

0. (130*» F.), 57.2*> C. (135^ F.). and 60** C. (140*» F.) 17 

2. Bacterial reduction during pasteurization for six hours at 62.8^ C. 

(145® F.). Plotted after one-half, three, and six hours 19 

3. Bacterial reduction during pasteurization for six hours at 62.8® C. 

(145® F.). Plotted every half hour 20 

4. Comparison of the mi Ik- tube and plate method for the determination 

of the bacterial groups in milk 23 

5. Bacterial groups of grade A milk before and after pasteurization for 

30 minutes at 62.8® C. (145® F.) 24 

6. Bacterial groups in grade A milk before and after pasteurization for 

30 minutes at 71.1° C. (160® F.) 26 

7. Bacterial groups in grade B milk before and after pasteurization 

for 30 minutes at 62.8® C. (145® F.) 26 

8. Bacterial groups in grade C milk before and after pasteurization for 

30 minutes at 62.8® C. (145® F.) 27 

9. Bacterial groups which survive pasteurization for 30 minutes at 76.7® 

C. (170® F.), 82.2® C. (180® F.), 87.8® C. (190® F.), and 93.3® C 
(200® F.) 28 

10. Changes in the bacterial group relations in grade A milk when de- 

termined by litmus milk reactions after different lengths of incu- 
bation. Milk pasteurized at 62.8® 0. (146® F.) for 30 minutes. . . 29 

11. Changes in the bacterial group relations in grade A milk when de- 

termined by litmus milk reactions after different lengths of incu- 
bation. Milk pasteurized at 71.1® C. (160® F.) for 30 minutes. . . 30 

12. Changes in the bacterial group relations in grade B milk when de- 

termined by litmus milk reactions after different lengths of incu- 
bation 31 

13. Changes in the bacterial group relations in grade C milk when de- 

termined by litmus milk reactions after different lengths of incu- 
bation 33 

14. Comparison of the percentage of the acid-forming bacteria in raw and 

pasteurized milk 33 

16. Comparison of the percentage of the peptonizing bacteria in raw and 

pasteurized milk 34 

16. Daily changes in the bacterial group relations in pasteurized milk. 

Sample G held at room temperature 39 

17. Daily changes in the bacterial group relations in pasteurized milk. 

Sample G held in the ice box 39 

18. Daily changes in the bacterial group relations in pasteurized milk. 

SuDple H held at room temperature 40 

7 



8 ILLUSTRATIONS. 

Page. 
Figure 19. Daily changes in the bacterial group relations in pasteurized milk. 

Sample H held in ice box 41 

20. Daily changes in the bacterial group relations in pasteurized milk. 

Sample K held at room temperature 42 

21. Daily changes in the bacterial group relations in pasteurized milk. 

Smnple K held in the ice box 42 

22. The acid-forming group of bacteria 44 

23. The alkali-forming group of bacteria 45 

24. The peptonizing group of bacteria 46 

25. Apparatus for the determination of gas production in milk 48 

28. Gas produced by culture Z 49 

27. A series. Cultures from milk pasteurized at 60'' C. (140'' F.) for 30 

minutes 54 

28. B series. Cultures from milk pasteurized at 65.6° C. (150'' F.) for 

30 minutes 56 

29. The hypothetical relation of the bacterial groups to raw and pas- 

teurized milk 62 

30. The hypothetical relation of the bacterial groups in raw and pas- 

teurized milk 63 



A STUDY OF BACTERIA WHICH SURVIVE PASTEURIZATION. 



INTRODTTCrnON. 

The bacteria which survive the process of pasteurization arc of great 
importance, since they form the foundation for the subsequent bac- 
terial development. It is well known that the most efficient pa8teu« 
rization will not destroy all of the microorganisms in milk. Hie 
process must, then, leave a certain number of bacteria which it is 
impossible to destroy at the temperatures employed. 

The prevailing view has been that the organisms left after heatiiig 
were largely of the peptonizing spore-forming type, with some few 
inert forms. This idea was based on the belief that all vegetative 
cells were destroyed at temperatures below the minimum pasteurizing 
temperature of 60*^ C. (140° F.). 

Theoretically, then, only spore-forming organisms should survive 
pasteurization. This view was strengthened by numerous investi- 
gations of the bacterial flora of boiled milk or milk pasteurized at 
extremely high temperatures. As lower temperatures came gradu- 
ally into use investigations indicated that vegetative cells might 
have higher thermal death points than was generally believedo 
Russell and Hastings * found a micrococcus which was capable of 
standing a temperature of 76*^ C. (168.8'^ F.) for 10 minutes. Other 
investigators pointed out that lactic acid bacteria occasionally ap- 
peared in pasteurized milk and yet the thermal death point of the 
lactic acid bacteria was stated to be in the neighborhood of 57.2*^ to 60® 
C. (135M40° F.). Rogers 2 found that in milk pasteurized at SB"" 
C. (185® F.) by the ''flash" process lactic acid bacteria occasionally 
survived. Marshall ^ states ''It is largely supposed that in pasteur- 
ized milk the lactic acid bacteria are lolled. This is largely true but 
not universally.'' Maz6* found that the ordinary lactic acid bacteria 

« Russell, H. L., and Hastings, E. O. A microooocos, the thermal death limit of which is 76* C. Cen- 
tralblatt fOr Bcktcriologle, Parasitenkunde nnd Inlektionskrankheiten, Abteilong 2, vol. 8, No. 11, pp. 
339-342. Jena, Mar. 13, 1908. 

« Rogers, L. A. The bacteria of pasteurized and unpasteurized milk under laboratory conditions. I'nitetl 
states Department of Agriculture, Bureau of Animal Industry, Bulletin 73. Washington, 1905. 

» Marshall, C. E. Pasteurization of millc Michigan Agricultural Experiment Station, Bulletin 147. 
Agricultural College^ August, 1897. 

« Maid, P. Pasteurization du lait destin<5 .^. la oonsommation. L'Industrie Laitiftre, vol. 32, No. 8, pp. 

121-127. Paris, Fob. 24, 1907. 

9 

67796**— Bull. 161—13 2 



10 BACTEBIA WHICH SUBVIVE PASTEUBIZATION. 

were destroyed by five minutes' heating at temperatures between 
SS'' and 65'' C. (131'' and 149'' F.), but that lactic acid bacteria existed 
which resist five minutes' heating at 76^ C. (IG?** F.). When milk 
was pasteurized in bottles for 60 minutes at 65® C. (149® F.), Grerber * 
and Weiske found that the bacteria which resisted belonged for the 
most part to the inoffensive lactic bacilli. An investigation of com- 
mercially pasteurized milk in this country carried on by the authors ' 
showed the presence of high-temperature resisting lactic-acid bacteria, 
the thermal death point of one of which was 77.8® C. (172® F.) with 
a 10 minutes' exposure and 75.6® C. (168® F.) with a 30 minutes' 
heating. It was further found that commercially pasteurized milk 
always soured. Kohler' and Tonney, after studying pasteurized 
milk in Chicago^ concluded that reinfection was the cause of the sour- 
ing of heated milk. 

It is evident that the knowledge of the bacteria which actually 
survive pasteurization is very limited. 

OBJBOT8 OF THIS INVESTiaATXON. 

The general object of this investigation was to study quantitatively 
and qualitatively the bacteria which survive pasteurization under 
conditions which excluded any possibility of recontamination of the 
milk after pasteurization. 

The special objects were as follows: 

1. To ascertain the average temperature of pasteurization in both 
the ''holder" and ''flash" process used throughout the country. 

2. To determine the effect of vanous pasteurizing temperatures 
for one-half hour's exposure upon the bacteria in different grades of 
milk. 

3. To study the effect of holding periods longer than one-half hour 
during pasteurization. 

4. To determine the effect of sudden cooling on bacteria after 
pasteurization. 

5. To study quantitatively the bacterial groups which survive 
pasteurization at various temperatures. 

6. To trace the development of the various bacterial groups in 
pasteurized milk held at different temperatures. 

7. To study qualitatively the bacteria which survive pasteurization. 

1 Qtther, N., and Weiske, P. Pasteurisation des flaoons dans ia grande Industrie (paatetiriaatton vno 
agitation). Revue Qte^rale du L4iit, vol. 2, No. 8, pp. 109-177. Lleire, Jan. 30, IQOS. 

* Ayers, 8. Henry, and Johnson, W. T., Jr. The bacteriology of oommercially pasteurised and raw 
market milk. United States Department of Agriculture, Bureau of Animal Industry, Bulletin 12ft. 
Washington, 19ia 

B Kohler, QottJMed and Tonney, F. O. The control of pasteurisation. Journal of the American Medloal 
AsBOdation, vol. M, Na 10, pp. 71S-718. Chicago, Mar. 11, 1911. 



METHODS EMPLOYED. 11 

MBTHObS. 

In this investigation the technique of plating and the preparation 
of beef infusion agar with a reaction of 1.5 (Puller's scale) was carried 
out according to the recommendations of the committee of standard 
methods for the bacteriological analyses of milk.^ In the prepara- 
tion of fermentation bouillons and litmus lactose gelatin, liebig's 
beef extract was used as a basis. 

Fermentation bouillons were prepared by dissolving 4 grams of 
liebig's beef extract and 10 grams of Witte's peptone in a liter of 
water and correcting reaction to 0.0 (Fuller's scale). The broth 
was then brought up to the sterilizing temperature for five minutes 
and filtered. When a clear filtrate was obtained, 0.5 per cent potas^ 
sium dibasic phosphate and 1 per cent of the substance to be fer* 
mented was dissolved in it. The following substances were used 
to test the fermenting ability of the bacteria: 

Sugars: Dextrose, galactose, lactose, saccharose, raffinose. Alco* 
hols: Mannite, glycerin. Starches: Inulin, wheat starch. Glucoside: 
Salicin. 

The ability of the bacteria to reduce nitrates to nitrites was shown 
by growing the organisms in a bouillon composed of 0.1 per cent 
Witte's peptone and 0.02 per cent potassium nitrate (nitrite-free) 
for 14 days at 30® C. (86° F.) and then testing for the presence of 
nitrites. The liquefaction of gelatin by an organism was deter- 
mined by inoculating with a drop of milk culture on the surface of 
the tube of medium and incubating for 30 days at 18° C. (64.4° F.) 
and then measuring the depth of liquefaction. 

Special media. — For ordinary routine plating of a milk sample, and 
especially for the determination of the peptonizing bacteria, a casein 
agar was devised,' consisting of dissolved chemically pure casein 
and i^ar, with a final reaction slightly acid. In isolating gas formers. 
Smith tubes containing lactose peptone bile * and dextrose liver broth * 
were used. 

All samples of milk were pasteurized in sterile flasks in the labora- 
tory. At all the temperatures except 60° C. (140° F.) and 65.6° C. 
(150° F.), 800 cubic centimeters of milk were heated. During the 
few experiments at those temperatures only 100 cubic centim- 
eters of milk were used. In all the experiments the period of 
heating was 30 minutes from the time the pasteurizing temperature 

1 Report of the Committee on Standard Methods of Bacterial Milk Analysis. American Joornal ot 
Public Hygiene, new series, vol. 6, No. 2, pp. 315-346. Colmnbus, Ohio, May, 1010. 

* Ayen, 8. Henry. Casein media adapted to determining bacteria in milk. United States Department 
of Agriculture, Bureau of Animal Industry, Twenty-eighth Annual Report, 1911 (in press). 

* Jackson, Daniel D. A new solution for the presumptive test for BadUut coU. Biological Studies ol 
Pupils of W. T. Sedgwick, pp. 29^200. BoeUm, 1906. 

* Jackson, D. D., and Muer, T. C. Liver broth. A medium for the determination of gas-fonning bacteria 
In water and sewage. Journal of the American Public Health Association, vol. 1, No. 12, pp. 927-929L 
Urbana, 111., December, 1911. 



12 BACTERIA WHICH SVRVIV^E PASTEURIZATION. 

was reached. The methods employed throughout this investiga- 
tion make the results comparable with those obtained by pasteuri- 
zation in sealed bottles. 

tempebatx7b.es ttsed thboughoxjt the coxtntbt. 

It was necessary to ascertain the temperatures most universally 
used at milk plants in this country in order that an average tempera- 
ture might be employed in these experiments. Circular letters 
were therefore sent to pasteurizing plants in nearly all cities with 
a population of over 25,000. RepUes showed that the average tem- 
perature with the "holder'' process was 62.8° C. (145*" F.). With 
the "flash'' process 71.1° C. (160° F.) was about the average. The 
reports from 219 milk plants which pasteurized showed that 76 used 
the "holder'' process and 144 the "flash*' process. 

Assuming that the correct temperatures for pasteurization are 
from 60° to 65.6° C. (140° to 150° F.) with the ^'holder " process, then 
62 of the 75 pasteurized at the proper temperature, one used a tem- 
perature too low, 54.4° to 57.2° C. (130° to 135° F.), and 12 too high, 
ranging from 66.7° to 76.7° C. (152° to 170° F.). With the ^^flash" 
process the correct temperature was assumed to be 71.1° C. (160° F.)- 
As there is usually a variation in the range of temperature during 
pasteurization, the maximum and the minimum given by each plant 
have been averaged. When the average was 71.1° C. (160° F.) it 
was assumed that the proper temperature was used. It was found 
that of 144 plants using the ** flash" process only 61 used the correct 
temperature, 61 pasteurized too low and 22 too high. The low tem- 
peratures ran down to 60° C. (140° F.), the high temperatures up to 
82.2° C. (180° F.). These figures show a decided lack of uniformity 
of temperatures used in pasteurization. The temperatures below 
60° C. (140° F.) with the ** holder" process render no protection as 
far as the destruction of pathogenic organisms is concerned, while 
those above 65.6° C. (150° F.) only increase the cost of pasteurization 
and tend to reduce the cream Une. The same is true when using the 
*'flash" process below or above temperatures ranging from 71.1° to 
73.9° C. (160° to 165° F.). 

As pasteurization is practiced, the milk might have been heated 
from 1 minute at 60° C. (140° F.) to 30 minutes at 76,7° C. (170° F.) 
and it would all be known as pasteurized milk. This lack of uni- 
formity is undoubtedly due to a misunderstanding of the effects of 
heat on the bacterial flora of milk. 



BACTERIAL REDUCTIONS. 



13 



BACTERIAL B.EDTJCTIONS BY LABORATORY PASTEURIZATION, 

USING THE <<HOLDER" PROCESS. 

Since regulations often require a definite percentage bacterial 
reduction and as the efficiency of pasteurizers is based on the same 
figures, it seemed advisable to study the quantitative bacterial reduc- 
tions under exact laboratory conditions. 

BACTERIAL REDUCTIONS AT 60° C.(l40° F.) AND 65.6^ C. (l50® P.). 

In these experiments the milk was heated in sterile flasks in a 
water bath at a temperature of 60° C. (140° F.) and 65.6° C. (150° F.) 
for a period of 30 minutes. The temperature recorded by a ther- 
mometer in the milk was maintained for the full 30 minutes. Twelve 
samples of milk from dairy X were used. Each was divided and a 
portion pasteurized at both temperatures. The counts were made 
on litmus lactose gelatin incubated at 18° C. (64.4° F.) for six days. 
Table 1 shows the total counts and efficiency of the process as deter- 
mined by the percentage bacterial reduction. An examination of 
the table shows that the raw milk was of poor quahty, having a high 
bacterial count. The samples pasteurized at 60° C. (140° F.) showed 
a high count, while the same samples at 65.6° C. (150° F.) showed a 
low count, as a rule. The effect of the few degrees of heat may be 
plainly seen. At the lower temperature 9 out of tlie 12 samples 
showed a reduction of less than 99 per cent, while at the higher 
temperature only 4 showed less than a 99 per cent reduction. 

Table 1. — Percentage reduction of bacteria by laboratory pasteurization^ iisingthe "holder^* 

process — Paw milk obtained from dairy X. 



Sample 
No. 


Raw mUk. 


Pasteurized at 60" C. 
(140- F.) for 30 
mlnutAs. 


Pasteurized at 
66.6'' C. (150T.) 
for 30 minutra. 


Total count. 


Total 
count. 


Percent- 
age re- 
duction. 


Total 
count. 


Percent- 
age re- 
duction. 


1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 


1 

33,900,000 200.000 
4,900,000 118,000 
5,060,000 130,000 
850,000 , 32,000 
6,100.000 20,200 
8,400,000 : 23,000 
1,670,000 1 284.000 
4,100.000 i 74,000 
1,120,000 ' 56,000 
4,800.000 • 153,000 
4.400,000 206.000 

12.300,000 I9('>,000 

1 


90.41 
97.59 
97.45 
96.23 
99.66 
99.72 
82.99 
98.19 
95.00 
96.81 
95.31 
98.41 


9,800 
12,300 
25,100 
26,500 
12,100 
12,600 
72,000 
28.500 
19,900 
19,800 
69,000 
40,000 


99.97 
99.74 
99.60 
97.00 
99.80 
99.85 
95.68 
99.30 
98.22 
99.58 
98.43 
99.67 



The effect of pasteurization on the bacterial content of another 
series of 12 samples from dairy Y was studied in the same way. 
The results are shown in Table 2. It may be seen that the milk 
was of far better quality than that from dairy X. The counts of 



14 



BACTEBIA WHICH SUBVIVE PASTEUBIZATION. 



milk pasteurized at 60® C. (140° F.) were low and still lower at the 
higher temperature. In spite of the low counts the percentage 
bacterial reductions were not so great as when a poor grade of milk 
was pasteurized as shown in Table 1. Eleven out of twelve samples 
showed a reduction of less than 99 per cent at 60® C. (140® F.). At 
S5.6® C. (150® F.) 7 out of 12 showed a bacterial reduction of less 
than 99 per cent. A comparison of Tables 1 and 2 show that the 
bacterial content after pasteurization of the better grade of milk 
was far lower than that of milk from dairy X, which contained a 
lai^e number of bacteria before heating. If, however, the efficiency 
of the process is studied, the higher percentage bacterial reductions 
will be found in Table 1, where the milk was of poor quality. It is 
very evident that the percentage bacterial reduction is of no value 
in determining the quality of pasteurized milk. Compare, for 
example, sample No. 1 in Table 1 with sample No. 3 in Table 2. In 
the first case, the raw milk contained 33^900,000 bacteria per cubic 
centimeter and after pasteurization 200,000 per cubic centimeter, 
which is a percentage reduction of 99.41 per cent. In the second 
case, raw milk, 128,000 bacteria per cubic centimeter and after 
pasteiuization 13,900 per cubic centimeter, which is a reduction of 
only 89.14 per cent. A 99.41 per cent reduction against 89.14 per 
cent, and yet the pasteurized milk in which only 89.14 per cent of 
the bacteria were destroyed was far superior in its bacterial content. 

Table 2. — Percentage reduction ofhacteria by laboratory pasteurizationf using the ^^ holder'^ 

process — liaw milk obtained from dairy Y. 



Sample 
No. 


Raw milk. 


Pasteurized atOO** C. 
(140» F.) for 30 
minutes. 


Pasteurised at 
66.6''C.(150"'F.) 
for 30 minutes. 


Total ootmt. 


Total 
ooont. 


Peroent- 
age re- 
duction. 


Total 
count. 


Peroentr 
age re- 
duction. 


1 

2 

3 

4 

6 

6 

7 

8 

9 

10 

11 

12 


2,500,000 

1,090,000 

128,000 

149,000 

600,000 

119,000 

108,000 

84,000 

160,000 

590,000 

2,900,000 

1,170,000 


27,600 

13,100 

13,900 

7,500 

16,400 

2,530 

1,890 

2,(300 

6,110 

13,200 

28,700 

34,100 


98.80 
98.79 
89.14 
94.96 
97.26 
97.87 
98.87 
96.90 
96.80 
97.76 
99.01 
97.08 


4,210 
2,320 
5,670 
3,100 

11,100 
1,020 
3,230 
2,720 
2,010 
7,100 

20.400 
3,560 


09.83 
99.78 
95.57 
97.91 
08.15 
99.14 
98.07 
96.76 
98.74 
98.79 
99.29 
99.69 



The uselessness of figures in expressing percentage reductions is 
further shown in Table 3. The bacterial content of 12 samples of 
milk before and after pasteurization has been averaged, two grades 
of milk having been used. While the percentage reduction is approxi- 
mately the same at 60° C. (140° F.) the average bacterial counts vary 



BACTEBIAL BEOUCTIOKB. 



15 



widely, one being 124,000 per cubic centimeter, the other only 13,900 
per cubic centimeter. At 65.6° C. (150° F.) while the percentage 
reduction is increased to 98 per cent, the bacterial content holds the 
same relation as at the lower temperature. 

Table 3. — Compariton of the average bacWialcc 
— t. J.- — -■_ 1— ',oT0 by paiUumalion at 60" 

AVERAOIS OF 13 BAUPLES IN EACH GRADE. 



Onid*. 


Rairndlk. 


PasteutiredatKCC. 
(IW F.) 30 mJDuUa. 


P»sl«ufliedat«s.B*& 

(IIO* F.) 30 mlDUMs. 


" 


par cubic 




p«r cubic 


Feremt 
ducUoD. 


Gradel..- 


7,a»,ooo 

804, OCO 


IM.OOO 

n,aoa 


B8,39 


28, BOO 


98.40 



BACTERIAL BEDUCTION AT 62.8' C. (l45°F.). 

Another, series of 28 samples of milk was studied in a similar man- 
ner. The results are shown in Table 4. In this series a tempera- 
ture of 62.8° C. (145° F.) was used for a period of 30 minutes. All of 
the samples of raw milk contained over 1,000,000 bacteria per cubic 
centimeter. The bacterial counts were made on infusion agar, incu- 
bated at 30° C. (86° F.) for six days. It may be seen from the table 
that the percentage reductions were high, only 3 out of 28 being less 
than 99 per cent; however, 13 of the pasteurized samples contained 
over 20,000 bacteria per cubic centimeter. 





Raw milk. 


P«gtaurliedBt82.S° 

C. (!«• F.) tor 30 

■ulnulec 


Sunple 


Bawmllk. 


C^O«^'h^» 


To^'" 


rH. 


Baclerls 


'*i^"^ 


Barleria 
per cubic 
KiHlmeWt 


BacWriB 


Bgereduo- 


1 

1 

12 
13 


iG,«a 

IS, MO 

IG.IOO 
K.000 

SB, TO 


000 

000 

000 

000 

coo 
ooo 

ooo 

no 

000 


ass 

18,300 

!■«! 

S:S8! 

s,soo 

.Siffi 

S,000 

11 


9S.4> 
M.K 

».8B 

n.w 

98.79 

9».W 
09.02 
W.82 
00.06 

S:!! 

S9.07 


S 
1 

i 


1! 00 

1 S 

S 00 
H 00 


IT. 

J 
1 


000 

000 

800 

800 

1 


I 
I 

»> 
as 

98 


7J 
96 

90 
88 

gs 

79 



16 



BACTERIA WHICH SURVIVE PASTEURIZATION. 



The results of similar experiments using a series of 24 samples of 
clean milk are shown in Table 5. The bacterial counts of the pasteur- 
ized milk were very low as a rule and yet 14 of the 24 samples showed 
a percentage bacterial reduction of less than 99 per cent. Sample 17 
contained, before heating, only 119,000 bacteria per cubic centimeter; 
after the process the bacterial content was 20,800, a reduction of only 
82.52 per cent. This sample evidently contained a high percentage of 
resistant bacteria which were able to withstand the process of pasteur- 
ization. From these results it is apparent that r^ulations of boards of 
health calling for a 99 per cent reduction of bacteria in commercial pas- 
teurization are of no value. As a general rule, it may be said that the 
higher the bacteria in raw mUk the greater the percentage reduction 
through pasteurization. When the bacterial content of milk is low it is 
almost always impossible to obtain a 99 per cent reduction of the bacte- 
ria. It is also evident that bacterial standards for pasteurized milk must 
not be set below the limit which it is theoretically possible to obtain. 
When pasteurizing in the laboratory for a period of 30 minutes at 
62.8° C. (145° F.) under conditions which permitted no reinfection 
of the milk, the bacterial content of pasteurized milk was by no means 
uniform. Sometimes the counts were high and sometimes low and 
yet the maintenance of the proper temperature of pasteurization 
would have assured in all cases the same degree of protection from 
pathogenic organisms. 

Table 6. — Efficiency of the * ' holder " process ofpasUjirization under laboratory ctmditioni, 
using raw milk with a bacterial content less than 1^000,000 per cubic centimeter. 



Sample 
No. 


Raw milk. 

Bacteria 

per cubic 

ceutl meter. 


Pasteurized at 02.8^ 
C (14,1- F.) for 30 

minutes. , 

1 


Sample 
No. 


Riw milk. 

Bacteria 

per cubic 

centimeter. 


Pa8tai]rliedate2.8* 

C. (145«F.)for30 

minutes. 


B^jt^f ' Per^nt. 

Umeter. ' "°"- 

1 ' 


Bacteria 
per cu- 
bic cen- 
timeter. 


Percent- 
age rediKV 
tion. 


1 

2 

3 

4 

5 

G 

7 

8 

9 

10 

11 

12 


372,000 

540,000 

410,000 

127.000 

143,000 

9.300 

18,100 

19,900 

5,300 

134,000 

300,000 


910 

2,330 

4,890 

1,170 

80 

765 

90 

180 

02 

34 

7,600 

t,600 


99.75 

99.46 ; 

99.09 

99.71 

99.93 

99.46 

09.03 

99.00 

99.68 

99.35 

94.40 

97.47 


13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 


640,000 

970,000 

102,000 

118,000 

119,000 

137,000 

15,600 

9,800 

18,700 

25,900 

15,300 

9,900 


11,800 

46,000 

8,400 

9,000 

ao,8oo 

3,100 
300 
100 

1,340 
830 
334 
320 


97.81 
95.25 
94.81 
92.37 
82.62 
97.73 
98.07 
96.97 
92.83 
96.79 
97.81 
96.76 



THE CONTROL OF PASTEURIZATION. 

The control of the process of pasteurization should be by bacterial 
limits for the milk which is to be used, together with supervision for 
the maintenance of the proper pasteurizing temperature and protec- 



EFFECT OF LONG HEATING ON BACTERIA. 



17 



tion against reinfection. The bacterial content of the milk will then 
consist only of those organisms which are able to withstand the tem- 
perature in use. 

EFFECT OF XiONQ HEATZNO ON THE BACTEBIA IN MTTiK. 

In some milk plants a holding period longer than half an hour is 
employed. It seems to be believed that an increased holding period 
produces a greater bacterial reduction. Several experiments were 
made at different tem- 



ysfloo 



-TO/kfO 




peratures and for dif- 
ferent periods in order to 
gain more information 
on this point. 

THREE hours' PAS- 
TEURIZATION. 

In order to determine 
the effect of a long pe- 
riod of pasteurization, 
milk was heated in ster- 
ile flasks at54.4^C.(130^ 
F.), 57.2° C. (135° F.), 
and60°C.(140°F.),and 
plated every half hour 
for three hours. The 
bacterial counts are 
shown in Table 6. One 
sample of milk was di- 
vided and a portion 
heated at the two lower 
temperatures, so the 
bacterial content of the 
raw milk was the same. 
The sample of milk 
heated at 60° C. (140° F.) contained approximately the same number 
of bacteria per cubic centimeter and was from the same dairy, so it 
is probably fair to compare the results. After one-half hour's heat- 
ing a much greater reduction was observed where the mUk was heated 
at 60° C. (140° F.). At the end of one hour's heating the bacterial 
content of the milk were more nearly alike and continued to show a 
gradual reduction throughout the three hours of heating. The final 
examination showed that the bacterial content was approximately 
the same in all the samples of milk. The bacterial reductions are 
shown better by the curves in figure 1 . It is evident that long heating 

67796**— Bull. 161—13 3 



Fio. 1.— Bacterial redaction daring pasteuiixatlon for three hours 
at 64.4"» C. (130» F.), 67.2« C. (136- F.), and 60* C. (140* F.). 



18 



BACTEBIA WHICH SUBVIVB PASTEURIZATION. 



at 54.4° C (130° F.) and 57.2° C. (135° F.) Lb of more value titan at 
60° C. (140° F.), as shown by curves A, B, and C, respectively. From 
a comparison of curves A and C it seems that one and a half hours' 
heating at 54.4° C. (130° F.) will produce as great a bacterial reduc- 
tion as one-half hour's heating at 60° C. (140° F.). It must not be 
assumed, however, that one and one-half hours' heating at 54.4° C. 
(130° F.) will destroy pathogenic organisms as surely as will one- 
half hour's heating at 60° C. (140° F.). That point can only be 
determined by experiment. 

Table 6. — Bacterial reduction during _pasteurizaUon for S Jufurs at 64.4° C. (130° F.), 

57.2° C. (1S5° F.), and 60° C. {140° F.). 



Temperature 
of 


Bacteria per 
cubic centi- 


Bacteria per cubic centimeter In milk pasteurized for— 


pasteuilza- 
Uon. 


meter in 
raw milk. 


ihour. 


Ihour. 


li hours. 2 hours. 

1 


2} hours. 


3 hours. 


•C. '*F. 
54.4 130 
57.2 135 
60.0 140 


2,530,000 
2,530,000 
2,330,000 


75.000 
63,000 
20,800 


27,600 
15,400 
19,400 


19,400 13,200 
12,600 1 8,400 
14,100 12,400 


12,300 

7,900 

10,300 


9.200 
5,600 
8,700 



SIX HOUBS' PA8TEUBIZATION . 

A similar experiment was made, using a six hours' period of heating 
at 62.8° C. (145° F.). In order to meet extreme conditions where 
the effect of long heating might show, a milk containing 27,000,000 
bacteria per cubic centimeter was selected. Plates were made e very- 
half hour during the period of heating. Table 7 shows the results. 

Table 7. — Bacterial reductions during pasteurization for 6 hours at 6t.8° C. {14S° F.) 



Length of 
pasteur- 
ization 
(hours). 

1 


Bacteria per 
cubic centi- 
meter. 


Length of 
pasteur- 
< isation 
(hours). 


Bacteria i)er 
cubic centi- 
meter. 


Raw 

I' 


27,000,000 
46,000 
46,000 
45,000 
65,000 
62,000 
54,000 


4 
6 


32,900 
31,200 
44,000 
35,700 
39,000 
34,500 



It may be seen that there was little difference in the bacterial reduc- 
tion produceci by a half hour's heating and by six hours' heating. 
There were numerous variations in the numbers of bacteria as deter- 
mined, but they were within the experimental error, as the flask of 
heated milk could not be thoroughly shaken. In this experiment the 
groups of bacteria which withstood the heating were determined. The 
plating was done on infusion agar plates, which were incubated at 



EFFECT OF LONG HEATING ON BACTERIA. 



19 



30® C. (86® F.) for six dayB. The plates were counted and then each 
colony picked from a plate and inoculated into litmus milk tubes. 
After 14 days' incubation the milk cultures were examined and as 
a result of the reactions shown the bacteria picked from the plates 
were divided into five groups, the acid forming and coagulating, acid- 
forming, inert, alkali-forming, and peptonizing groups. The value 
of this method of determining bacterial groups will be discussed later 
in this paper. Figure 2 shows the relations of the groups after heat- 
ing one-half hour, three hours, and six hours. The acid-coagulating 
and simple acid-forming 



75 



70 



€S 



€0 



ss 



so 



\ 



Sj5 



2S 



20 



/5 



iO 




groups composed the 
largest portion of the 
bacteria after a half 
hour's heating and the 
same after six hours' 
pasteurization. It may 
be seen, however, that 
the percentage of the \^^ 
acid-coagulating group ^^^ 
was reduced by the 
heating for six hours. 
It seems probable that 
the heating weakened 
the activity of the acid- 
forming bacteria so that 
in the litmus milk tubes 
not enough acid was 
produced to coagulate 
the milk in the 14 days' 
incubation period. 
That would result in a 
lowering of the percent- 
age of the acid-coagulating group, while increasing at the same time 
the simple acid-forming group. The percentage of the alkali and 
peptonizing groups was extremely low throughout the experiment. 
In figure 3 the group percentages have been plotted at every half 
hour's sampling and gives a more complete picture of the changes 
in the bacterial groups. The changes in the group percentages 
between three and one-half and four hours is undoubtedly due to the 
errors in sampling and inaccuracy of the method of the bacterial 
group differentiation. 



FiQ. 2.— Bacterial reduction during pasteurixation for six hours at 
62.8" C. (145<* F.). Plotted after one-half, three, and six hours. 



20 BACTEEIA WHICH SURVIVE PASTEURIZATION. 

EFFECT OF STJBDBN OOOUNO OH THE BACTEBIA IN PASTEtTBIZBD 

The sudden cooling of the hot milk after pasteurization has been 
considered by many to be an essential part of the process. It was 
believed that the sudden change from hot to cold aided in. the destruc- 
tion of the bacteria. 
In the recent develop- 
ments of the process of 
pasteurization, how- 
ever, this opinion lost 
ground, although at the 
. present time thei-e are 
i tliose w)io still believe 
! in its value. In order 
I to throw light on this 
point a few experi- 
I ments were made under 
1 laboratory conditions. 
Samples of milk were 
pasteurized in sterile 
flasks, then cooled by 
running through a 
sterile copper coil sur- 
rounded by brine into 
I another sterile flask. 
Table 8 shows the results 
of tlie experiments. 
Two samples of milk 
were pasteurized at 
62.8° C. (146° F.) for 30 
minutes, tlien cooled in 
15seconda to from 1.7°- 

3.9° c. (sso-sg" F.). 

FiO. 3.— Bictertalrednctton during paeWurliMlon tor eii boon at The experiment WaS TO- 
W.8* C. (!«• F.). Plolled every ball hour. , j ■ ■ j 

peated, using a period 
of 30 minutes' heating at 71.1° C. (160° F.). The bacterial content 
of the milk before and after cooling was approximately the same, the 
differences always being within the limits of experimental error. It is 
evident from the results shown in the table that sudden cooling is 
of no value in causing a destruction of bacteria, at least not at the 
temperatures used in the experiments. 



BACTERIAL GROUPS. 
Table 8. — Effect ofsvdden cooling on the bacterial content of pasteurized milk. 



21 



Sample 
No. 


Bacteria 

{Mr cubic 

centimeter 

In raw 
milk. 


Pasteurized at 62.8* C. 
(145*F.)30minut4^. j 


Sample 
No. 


Bacteria per 
cubic centi- 
meter in raw 
milk. 


Pasteurized at 71. !•€. 
(160»F.) 30 minutes. 


Bacteria 

per cubic 

centimeter 

In milk 
not cooled. 


i 

Bacteria ' 

per cubic 

centimeter ' 

in cooled i 

milk. 


Bacteria 

per cubic 

centimeter 

inmUk 
not cooled. 


Bacteria 

per cubic 

centimeter 

in cooled 

milk. 


1 . 
2 


186.000 
233,000 


8,600 
1,470 


8,500 ' 
2.160 


3 

4 


400.000 
1,350,000 


1.880 
1,750 


1,950 
1,700 



The value of sudden cooling then, lies in the fact that milk after 
pasteurization is not allowed to cool slowly through temperatures 
below 37.8° C. (100° F.) where a rapid development of bacteria might 
occur. 

GBOTTPS OF BACTBBIA WHICH ST7BVIVE PASTETTBIZATION. 

The most important feature of this investigation has been the 
determination of the various groups of bacteria which survive the 
process of pasteurization. These bacteria form the basis of the 
bacterial growth in pasteurized milk. 

GRADES OF MILK STXTDIED. 

Since the bacterial groups in various grades of milk vary with the 
quality of the milk, it was decided to examine three grades — one of 
poor quality, one of fair quality, and one of good quality. The 
bacterial content of each of the samples of the three grades has been 
averaged as shown in Table 9. With poor milk designated grade A, 
the average of 20 samples showed a bacterial content of 32,950,000 
per cubic centimeter. An average of 24 samples of grade B showed 
3,451 ,000 per cubic centimeter, while tlie average bacterial count of 12 
samples of grade C milk showed 24,700 per cubic centimeter. 

Ta B LE 9 . — Grades of m ilk st udied. 



Grade. 


Average 
number of 

bacteria 

"per cubic 

centimeter. 


Number 

of 

samples 

averaged. 


A 
B 
C 


32.950,000 

3.451.000 

24,700 


20 
24 
12 



METHODS. 



In the determination of the bacterial groups a method was employed 
which may be designated as the milk-tube method. This method, as 
described earlier in this paper, consists in picking off each <;olony on 
the plate and inoculating it into litmus milk tubes. The milk tubes 



22 



BACTEBIA WHICH SUBVIVE PASTBUBIZATION. 



were incubated for 14 days at 30° C. (86° F.), and the bacteria from 
the plate were then divided into groups according to the reactions 
which they produced in the litmus milk tubes. By using this method 
it was possible to divide the bacteria developing on a plate into five 
groups, namely, the acid-forming and coagulating, the acid-forming, 
the inert which produce no change in milk, the alkali-forming, and 
the peptonizing groups. The acid-coagulating and the acid-forming 
groups are not necessarily composed of distinct organisms, although 
the acid-coagulating group probably included organisms which 
always coagulate milk, and in the acid group there are undoubtedly 
bacteria which never coagulate milk. The bacteria were divided by 
the reaction in litmus milk after incubation for 14 days at 30° C. 
(86° F.). It is impossible by the ordinary method of plating on 
litmus lactose gelatin to separate the alkali-forming bacteria from 
those which are inert on gelatin on account of the fact that colonies 
of alkali-forming bacteria on litmus lactose gelatin plates do not form 
enough alkali to produce a change of the litmus. The alkaU and 
inert groups must then be classed together and also include acid-form- 
ing bacteria which do not produce enough acid to give a red coloration 
on the plate. 

In order to show the value of the tube method a comparison with 
the plate method was made. Four different samples of milk were 
used, a portion of each being heated to 60° C. (140° F.) and also 
65.6° C. (150° F.). The pasteurized milk was then plated on litmus 
lactose gelatin plates which were incubated at 18° C. (64.4° F.) 
for six days. A differential count was then made of the acid-forming, 
alkali or inert, and the peptonizing colonies. After counting, the 
colonies were picked off and inoculated into litmus milk in order to 
complete the milk-tube method. The results of the experiments are 
shown in Table 10. It may be plainly seen that the plate method 
was very inaccurate. The percentage of the acid group of bacteria 
was always increased by the milk-tube method of differentiation, and 
the alkali or inert groups were decreased. 

Table 10. — Comparison of the milk-tube and plate methods for the determination of the 

bacterial groups \n milk. 



Sample 
No. 


Temperature 
of heating. 


Acid group. 


Alkali or inert 
group. 


Peptonixing group. 


Milk- 
tube 
method. 


Plate 
method. 


Milk- 
tube 
method. 


Plate 
method. 


Milk- 
tube 
method. 


Plate 
method. 


1 
1 
2 
2 
3 
3 
4 
4 


60.0 140 
65.6 150 
60.0 140 
65.6 150 
60.0 140 
65.6 ISO 
60.0 140 
65.6 150 


Per cent. 
73.21 
76.68 
62.29 
77.89 
58.39 
94.36 
92.17 
90.64 


Percent. 
58.73 
56.96 
25.15 
12.93 
34.35 
45.68 
66.37 
49.41 


Per cent. 

16.07 

11.01 

35.16 

18.95 

32.83 

4.83 

7.25 

7.20 


Percent. 
40.21 
41.79 
72.32 
86.20 
58.77 
52.15 
42.64 
60.58 


Percent. 

10.71 

13.30 

2.54 

3.15 

8.75 

.80 

.56 

2.15 


Percent. 
1.05 
1.24 
2.52 

.86 
6.87 
2.15 

.98 





BACTEBIAL GROUPS. 'Hi 

Usually the peptonizing group of bacteria was also increased. 

The differences in the differentiation of the bacterial groups is 
shown graphically in figure 4. The bacterial flora of four samples of 
milk pasteurized at 60° C. (140° F.) as shown by averages and deter- 
mined by the plate method consisted of 43.65 per cent of the acid 
group, 53.48 per cent of alkali or inert group, and 2.85 per cent of 
the peptonizing group. When determined by the milk-tube method 
the group percentages were changed to 71.51 per cent of the acid 
group, 22.83 per cent of the alkah or inert group, and 5.64 per cent of 
the peptonizing group. 

When milk was pas- 
teurized at 66.6° 0.(150° 
F.) there were marked 
differences in the bacte- 
rial flora when determ- 
ined by the two methods 
(see fig. 4). Jhe re- 
sults from four samples 
were averaged. As de- 
termined by the plate 
method the bacterial 
flora consisted of 41.24 
per cent of the acid 
group, 57.68 per cent of 
the alkali or inert group , 
and 1 .06 per cent of the 
peptonizing group. 
When determined by 
the milk-tube method 
the percentages were 

changed to 84.64 per rio.4._con.p»b»n<.f tli.mllk-tul«»ndpK.Um«.hodtorlhe 
cent of the acid group, dewrmlnatloD of the bsftOTla! groupa In milk. 

10.49 per cent of the alkali or inert group, and 4.85 per cent of the 
peptonizii^ group. It is evident from these experiments that the milk- 
tube method was much superior to the litmus lactose gelatin plate 
method of differentiation. Its advantages may be summarized as 
follows: 

1, The milk-tube method is more accurate than the plate method 
for the differentiation of bacteria into groups. 

2, It is possible by this method to separate the alkali-forming 
group of bacteria from the inert group, which is not possible on lit- 
mus lactose gelatin plates. 

3, The activity of the bacteria in the various groups can to some 
extent be determined by their abihty to produce changes in litmus 
milk after various lengths of incubation. 



BACTBBU WHICH BURVIVB PASTEURIZATION. 



ACfO 

CQASULATim 

^«/7 



THE BACTERIAL GROUPS IN GRABE A MILK BEFORE AND AFTBB PAS- 
TBUBIZATION FOR 30 UINUTE8 AT 62.8° C. (145° F.). 

Throughout the study of the bacterial groups in. rnw and pasteur- 
ized milk the milk-tube method of differentiation has been used. 
The plating was on infusion agar, which was incubated for six days 
at 30° C, (86° F.). The milk used in the first experiments was of 
poor quality and constitutes grade A milk. Pasteurization was per- 
formed in sterile flasks 
^^^ and heated in a water 

"^^^ bath for 30 minutes at 

62.8°C. (145°F.). The 
percentage of the differ- 
ent bacterial groups was 
determined before and 
after pasteurization of 
the milk. In order to 
show the results in the 
most simple manner the 
group percentages of 10 
samples of rawmilk and 
12 of pasteurized milk 
have been averaged and 
are shown graphically 
in figure h. The aver^ 
age of the total acid 
group in raw milk was 
46.88 per cent of the 
total bacteria. After 
pasteurization the per- 
centage was increased 
to 79.78 per cent. The 
acid coagulating group 
was decreased from 
36.17percenttol7.91 percent. Theinertgroupwasalsodecreasedand 
the alkali group slightly increased, from 6.47 per cent to 9.77 per 
cent, which was due to the averaging of one sample of pasteurized milk 
which was exceptionally high in the percentage of the alkali formers. 
The peptonizing group was decreased from 17.31 per cent in the raw 
milk to 1.39 per cent in the pasteurized milk. These results are most 
striking in so far that they are contrary to the most generally accepted 
ideas of tiie effect of pasteurization on the bacterial flora of milk. 



/tAi¥ 



BAOTEEIAL GB0UP8. 



AGIO 



THE BACTERIAL GROUPS IN ORADB A MILE BEFORE AND AFTER PAB-^ 
TEUHIZATION FOB 30 MINUTES AT 71.1° C. (160° F,}. 

A second set of experimente was made, using grade A milk which 
was pasteurized at 71.1° C. (160° F.) for 30 minutes and examined 
in the same manner as before. The averaged results of five samples 
of raw and six samples of pasteurized milk are shown in figure 6. 
The changes in the 
bacterial groups were /«io 

about the same as at ''-X 

62.8° C. (145° F.). 
While the percentage 
of the total acid group 
was higher than in the 
r"i)k pasteurized at 
the lower tempera- 
tures, it will 1)6 seen 
that the percentage of 
the acid-coagulating 
group was smaller. 
The acid group was 
made up laigely of 
slow acid-forming or- 
ganisms, as will be 
shown later. The 
alkali group was re- 
duced and the pepton- 
izing group reduced 
from 16.26 per cent 
in the raw to 0.53 per 
cent in the pasteurized 



THE BACTEKIAL GROUPS IN GRADE B MILK BEFORE AND AFTEH PAS- 
TEURIZATION FOR 30 MINUTES AT 62.8° C. (145° F.). 

The same experiments were repeated, pasteurizing a better quaUty 
of milk, grade B, at 62.8° C. (145° F.). The averaged results of 17 
samples of raw and 20 samples of pasteurized milk are shown in figure 
7. The total acid group was increased from 22.72 per cent in the 
raw to 66.76 per cent in the pasteurized milk. It will be noticed that 
the acid-coagulating group was increased from 12.98 per cent to 
31.89 per cent in the pasteurized milk. The alkali and peptonizing 
groups were reduced from 19.66 per cent to 5.63 per cent and from 
14.10 to 3.59 per cent, respectively. 
67796°- Bull. 161—13 4 



26 BACTEEIA WHICH SURVIVE PASTEURIZATION. 

THE BACTERIAL GHOUFS IN GRADE C MILK BEFORE AND AFTER PAS- 
TEURIZATION FOR 30 MINUTES AT 62.8° C. (145° F.). 

A third grade of milk of good quality, grade C, 'waa studied 
in the same maimer as the other grades. The percentage of the 
various bacterial groups changed in a similar manner as in the other 
experiments. The milk was pastemized for 30 minutes at 62.S° C. 
(145" F.). Figure 8 shows the averaged results. It may be seen 
that again the total acid group was increased in percentage from 
40.70 per cent to 73.10 per cent of the total bacteria. The acid- 
coagulating group, 
however, decreased in 
percentage from 33.85 
, per cent to 11.85 per 

''^'^ cent. All the other 
groups were decreased 
in their percentage by 
pasteurization. These 
results show that in- 
stead of the acid-form- 
\3Aff9 ™^ bacteria being 
destroyed by pasteuri- 
zation they were ac- 
tually increased in 
their percentage of 
f the total bacteria sur- 

\zAOO viving the process. 
[ This does not mean 

/ that there were greater 

\s€3 numbers of acid-form- 
).2Ja ing bacteria after 
^AW f*^S7Sy/7/z£0 pasteurization but 

>W^ffl^5 "^««^y *^''* * greater 
™ and art™ paaieuri- percentage of the bac- 
*** *■■'■ teria in pasteurized 

milk Were of the acid-forming group than in the milk before heat- 
ing. The percentage of the other groups was lowered by pasteuri- 
zation. This is of particular interest in the case of the peptonizing 
group, which has been believed to constitute the majority of the 
bacteria which survive the heating process. It must be remembered 
that these results apply for the most part to mUk pasteurized at 
62,8° C. (145° F.), although they hold for the few samples studied 
which were heated at 71.1° C. (160° F.). So far as the practical side 
is concerned, oidy the results at 62,8° C, (140° F.) are of value, for 
the Jiigher temperatures are seldom used in commercial work. 



BACTBBIAL QBOUPS. 



TH£ BACTERIAL GROUPS IN MILK PASTEURIZED AT HIGH 
TBMFEHATURES, 

In order to determine the bacteria which survive pasteurization 
at high temperatures, the bacterial groups were detennined by the 
milk-tube method in seven samples of milk. Two samples were 
pasteurized at 76.7° C. (170° F.), three at 82.2° C. (180° F.), one at 
87.8° C. (190° F.), and two at 93.3° C. (200° F.). All were heated in 
sterile flasks and the temperatures held for 30 minutes. The per- 
centages of the bacterial groups have been averaged at each temper- 
ature and are shown 
in figure 9. It will be 
seen that even at 76.7° 
C. (170° F.) a large 
percentage of the acid- 
forming group was cqA6UL 
found, the percentage 33.1 
of the total acid-form- 
ing group, including 
both the acid-coagulat- 
ing and the simple acid- 
forming group, being 
80.91 per cent. The 
bacteria of this group, 
however, produced 
acid very slowly, which 
differentiates them 
from' those which sui^ 

vive at lower tempera- -* ' 

tures. An increase in 
the percentage of the ^^'^ 
peptonizing group 

over that at the lower .fl4*v 

temperatures is notice- 
able. The average per- FiQ. 8-~Buterlal groups id gmteCmllk before and after putauiiia' 

centage of the pepton- 
izing group at 62.8° C. (145° F.) ranged from J.39 per cent to 4.47 per 
cent in three grades of milk. At 71.1° C. (160° F.) the percentage was 
0.53 per cent, while at 76.7°C. (170° F.) it was increased to 7.25 per cent. 
The increase is of course produced by the greater destruction of the other 
groups. At 82.2° C. (180° F.) a distinct change took place in percentage 
of the groups which survived the heating. The acid group was reduced 
greatly, while the peptonizing group was increased to 68.12 per cent 
of the total bacteria. The alkali group comprised 16.08 per cent of 
the bacteria, which is evidently a very high average. If a large 
number of samples bad been studied, the average percentage of the 






28 BACTEBIA WHICH SUBVIVE PA8TETIBIZATI0N. 

group would have probably been very low, since at 71.1° C. (160" P.) 
and 76.7" C.(170'* F.) only a very small percentage survived. The 
bacterial groups at the higher temperatures were similar to those at 
82.2° C. (180° F.). The almost total absence of the acid-coagulating 
group and the low percentage of the acid group, together with the 
high percentage of the peptonizing group, is very noticeable. 

THE AOTIVITY OF BACTEBIA OF THE VAUIOXTB GBOUFS ISOLATED 
FROM RAW AND PASTBUItlZBD KELK HBASUBED BT THEIR 
ABUJTT TO PROD17CE CHANQES IN IJTICtTS HXLE AfTBR DIF- 
FERENT LENOTHS OF IHC1TBATI0N. 

The activity of the bacteria found in raw and pasteurized milk is 
important since acid-forming bacteria which coagulates milk in 48 
hours produce a more normal souring in pasteurized milk than the 
slow acid - producing 
forms which may be 
,,,,■*« overgrown by the pep- 

*• tonizing bacteria. Or- 

ganisms of the pep- 
tonizing group which 
cause peptonization 
rapidly are of far 
greater importance 
than those which re- 
quire long incubation 
to produce changes in 
^^g mUk. During the de- 

■ termination of the bac- 

no.9.-B«!tortol group, whkhsurvlTepeaWariratfonfof TO min- ^^"^ gTOUpS by the 

utM at 76.7* c. (iTo* F.). S2J!" c. (iso-F.), «!.» c. (iw F.), and milk-tube method the 
reactions produced by 
the different cultures of bacteria were recorded after 2, 5, and 14 days' 
incubation. The length of time required to produce changes in litmus 
nulk served as a measure of the activity of the culture. It then fol- 
lows that the changes in the group relations as determined by the 
litmus milk tube reactions gave a general indication of the activity 
of the bacteria which composed the group. 

The activity of bacteria of the various groups isolated from three 
grades of milk has been studied. 

GRADE A MILK BEFOKE AND AFTER PASTEURIZATION AT 62.8° C, 
(145° P.) FOR 30 MINtlTBB. 

The results shown in Table 1 1 indicate the rapidity of the growth of 
the bacteria of the various groups isolated from milk before and after 
pasteurization at 62.8° C. (1^" F.) as measured by their ability to 
produce a change in litmus milk. As may be noted from the table, 



BACTERIAL GROUPS. 29 

plates were made of icfusion and casein agar and the colonies develop- 
ing on each medium were picked off and differentiated by the tube 
method. The group percentages in the table represent the average 
of a number of samples. In general it may be said that casein agar 
seemed to favor the growth of the alkali forming and the peptonizing 
bacteria so that their group percentages were usually higher when 
determined on that medium. In order to show the reaiilts more 
plainly the averages have been plotted as shown in figure 10. The 
blocks in the columns represent the bacterial group percentages 
determined by the tube method after 2, 5, and 14 days' incubation in 
milk. The column at 2 days, for example, shows the group percent- 
ages determined by the reactions of the colonies picked from an 
infusion agar plat«. 
The percentages were 
determined by the re- 
actions of fhe milk tubes 
after 2 days' incubation 
at 30° C. (86° F.). The 
tubes were then incu- 
bated for 3 days more 
and the group percent- 
ages again determined 
- by the reactions. Incu- 
bation was then contin- 
ued for 14 days, when 
the final reactions were 
recorded. The figure 
shows that the percent- 
age of the total acid ^--^-^/r ^^^^^^"^ 
group was greater in raw som^wtes 

• n tt L J I Pio- 10.— Changes in Uw bacterial group nlstioDs iD grade A mltk 

milk after two days wheDdMermlDedbylitmusnilltreMHonsariercilfferentleQgthfl 
incubation than in pas- "' '°™'>atioii. uiik pasteuriad at st.t' c. (hs* f.) tor 3o 
teurized. Afterfive 

days, however, the total acid group was higher in percentage in 
pasteurized milk. After 14 days the total acid group in pasteurized 
milk was much larger. This shows that the bacteria of the acid 
group in pasteurized milk develop slower, or at least produce acid 
slower, than those in raw milk. Since the differentiation of the 
groups was based on the change prbduced in litmus milk by the bac- 
teria, it may be seen from the figure that as a rule the alkali-forming 
bacteria did not develop enough alkali to change the color of litmus, 
which differentiates them as belonging to the alkali group, until the 
fifth day of incubation. While the figure may seem rather comph- 
cated, a careful study clearly shows the difference in the bacterial 
groups in raw and pasteurized milk based on the rapidity with which 
they produce changes in htmus milk. 



3U BACTERIA WHICH SURVIVE PASTEURIZATION. 

Table 11. — Changa in the bacUrial group relation* in grade A mili idim drlermintd Irg 

litmiumilt reactiont after different length* of ineubatton — Milk p<utturiud at 61.8° C. 
045° F.)/or SO minuUt. 





l4iruilon Kpu ptat«. Casein a«u pUa. 


B«««itoie™ii« 


»...«». 


I'asuuriird milk. 


Raw milk. Paslcuriud milk. 




■days. ! days. , day*. 


daj™. 


days. [ d^s. 


4. 


«.k 


It 2 
daj-s. days. 


d^s. 


di^ 




Per a. 

24.11 
18.08 
42.M 
1.20 

w.na 


Pff«. per a. 
32.72 36.17 
14. «4 10.71 

33.23 2».3I 


Peru. 

6.01 

le.Di 

74.89 
'.7» 


Pad. Pact. 

4g!oi Bl!s7 
35.13 9.06 


Ptra. 


Ftrel. 

16.96 

fi.N 
17.04 


32!99 


Per a. 


Paet, 

4z.n 

48.07 
4.17 
.02 


^^S 










Peploniilng 


1.30 


Total 


W.flS 98.97 


99.99 


99.»! lOO.OOl 99.97 


99. W 


99.97 99.07 


99.07 199.98 


Number of »m- 


,. 


,.' ,. 


12 


■J „i 7 


,\ , ,. 


10 ' 10 



OBADB A MILS BEFORE AND AFTER PASTEUItlZATlOX FOK 30 MINIATES 

AT 71.1° C. (160° F.}. 

Earlier in tliis paper it was shown that the percentage of the total 
acid group was higher in grade A milk pasteurized at 71.1° C. (160" 
F.) than at 62.8° C. (145° F.). It ia natural to suppose, then, that 
milk pasteurized at the higher temperatures would sour more quickly 
than when heated at the lower temperatures. Such is not the casCf 

however; first, because 

^ the total number of 

bacteria are less in the 
milk pasteurized at 
71.1°C.(160°F.),and, 
second, because the 
acid group of bacteria 
is less active. This 
last reason is shown 
by the changes in the 
bacterial group rela- 
tions as determined in 
litmus milk by differ^ 
ent lengths of incuba- 
^B^"* tion. Table 12 shows 

the averaged group 
>M^««A- m*ai^^^^ percentages deter- 

*>-^w j^j^gj jj^m infusion 

M bacterial groQp relations In gmile A milk wbcD 

tiooaafierdurenDt lengths oiiDcu- and casem agar plates. 
i-c.(i60-F.)tor30minat«. ^^^ results are shown 

to better advantage in figure 11, It will be noticed that after two 
days' incubation only a small percentage of acid-forming bacteria 
were retxjrded in the pasteurized milk and none of the acid-coagulat- 



BACTERIAL CBOUPS. 81 

ing group. After five days the acid group was increased greatly, but 
there was only an extremely small percentage of the acid-coagulating 
group. Even after 14 days' incubation the reactions showed only a 
small percentage of the acid-coagulating group. In both raw and 
pasteurized milk the slow growth of the alkali group is shown by the 
fact that only a small percentage was found in the raw milk after 
five days' incubation of the litmus milk tubes, while none was found 
in the pasteurized milk until after 14 day^' incubation. 

Table \2.—Changa in tht baeUrial group relalioni h 
lUmii* mitt rtacliont a/Ur different length* o/incuba. 
{160° F.)foT30minutel. • 







Inliulon igar pUtn. 


mint. 


CuelD ag»r plat*s. 


BKWrial 


RawmUlc. 




Rsirmllk. 


Pastaurlied milk. 




^„. 


d^s. 1 dijs. 


,.v 


d.V 


daj". 


dsyt 


( 1 » 


.k 


day^ 


dayi. 


Ac,d«»^.. 


Pircl. 
62. » 


PfTd. Pert. 


'""■ 


Pntt. 


Ptta. 


Pa ft. 


Pati.\Pact. 
K.ff. 47:^8 


Pna. 


Pird- 


Pirct. 




M.Sl 43.S1 i 87.88 


vi.K 


7U.10 












PeplDDUlDg... 


14.11 


.06 


.M 


.70 


ToUl 


w.M Im-wtl w.ii7|M.gs 


m.m 


ion. 00 


99. BS 


99.SBlM.aS 


B9.9R 


99.99 


99.96 


Numberornm 


•1 .| .| . 


e 


c 


9 


9 B 


■■ 


11 


" 



GRADE B UILK BEFORE AND APrEB PASTEURIZATION FOR 30 UINITrES 
AT 62.8° C. (145° F.) 

The changes in the bacterial group relations determined by the 
milk-tube method after 
various lengths of incu- *»^ 
bation showed a diffei^ 
ence from those in grade 
A milk. Table 13 shows 
the averages of the group 
percentages which are 
plotted in figure 12. A 
study of the plot shows 
that the percentage of 
the total acid group and 
the acid - coagulating 
group itself was greater 
in the pasteurized milk a»7» 

after the two days' in- a*ys-^z s m anrs-,.e a ^ 

cubation period than in 
the raw milk. In other 
words, the activity of ^o. i 

the acid-producing or- Tf'^ta'S^™'" ' "■" ' "" 

genisms which survived 

the heating was as great as those in raw milk. The reason for the 
difference in the two grades of milk is not apparent. 



32 



BACTERIA WHICH SURVIVE PASTEURIZATION. 



Table 13. — Changes in the bacterial group relations in ^ade B milk when determined by 
litmus milk reactions after different lengths of incubation — Milk pasteurized at 62. 8*^ U. 
{14S° F.)for SO minutes. 





Infusion agar plates. 


Casein agar plates. 


Bacterial 
groups. 


Raw milk. 


Pasteurized milk. 


Raw milk. 


Pasteurized milk. 




2 
days. 


5 
days. 


14 
days. 


2 
days. 


5 
days. 


14 
dajrs. 


2 
dajrs. 

Perct. 
6.14 
4.67 

81.37 

.09 

7.69 


5 
days. 

Peru. 
7.66 
5.17 

66.89 
6.53 

13.73 


14 
days. 


2 
days. 


5 

days. 


14 
da3^ 


Acid coagulat- 
ing 


Perct. 

6.59 

11.39 

73.45 

.21 

8.35 


Perct. 

9.54 
12.55 
58.04 

7.86 
11.99 


Perct. 
12.98 
9.74 
43.51 
19.66 
14.10 


Perct. 
20.05 
11.27 
67.46 

"i"2i 


Perct. 

23.12 

27.48 

45.02 

2.39 

1.98 


Perct. 
31.89 
31.87 
24.00 
5.63 
3.59 


Perdt. 
8.45 
7.18 
50.09 
17.79 
16.47 


Perct. 

10.58 
6.72 

82.30 
.03 
.35 


Perct. 

12.86 

27.98 

55.84 

2.43 

.87 


Perct. 

18.73 


Acid 


29.72 


Inert 


40.63 


Alkali 


7.92 


Peptonizing 


2.99 


Total.... 


99.99 99.98 


99.99 


99.99 ! 99.99 


99.98 


99.96 


99.98 j 99.96 


99.98 


99.98 


99.99 


Number of sam- 
ples averaged 


1 

16 17 17 1 19 ' 20 

1 1 


20 


17 


18 


1 
18 ' 21 


22 


22 



GRADE C MILK BEFORE AND AFTER PASTEURIZATION FOR 30 MINUTES 

AT 62.8° C. (145° F.) 

When grade C milk was studied in the same manner, the per- 
centage of the acid-coagulating group in pasteurized milk was found 
to be small and the group inactive. The averaged results in Table 14^ 
and shown graphically in figure 13, bring out this point. It will be 
seen that the acid-coagulating group percentage was very small up 
to the 14 days' incubation period. The acid group also was rather 
inactive as indicated by the percentages. A large part of the pepton- 
izing group developed slowly, as indicated by the increase in the 
percentage of groups shown in the various plots. 

Table 14. — Changes in the bacterial group relations in ^ade C milk when determined by 
litmus milk reactions after different lengths of incubatwn — Milk pasteurized at 62.8^ C. 
{14S° F.)for SO minutes. 







Infusion agar plates. 






Casein agar plates. 




Bacterial 
groups. 


Raw milk. Pasteurized milk. 

1 


Raw milk. 


Pasteurized milk. 




2 
days. 


5 
days. 


U 
days. 


2 

days. 


5 
days. 


14 
days. 


2 
days. 


6 
days. 


days. 


2 
days. 


5 
days. 


14 
days. 


.\cid coagulat- 
ing 


Perct. 

18.10 

15.18 

64.54 

.20 

1.96 


Percv. 

31.33 
9.12 

49 44 
1.66 
8.13 


Perct. 
33.85 

6.85 
43.13 

3.33 
12.81 


Perct. 
0.06 
6.82 

91.21 

"i.89' 


Perct. 

0.35 

43.02 

53.46 

.06 

3.09 


Perct. 

11.85 

61.25 

22.06 

.36 

4.47 


Perct. 
7.25 
6.59 

84.53 

"i'.hi' 


Perct. 
9.96 
7.17 

76.09 
l.ll 
5.65 


Peru. 
9.90 
7.94 

63.79 
5.90 


Perct. 
0.36 
1.96 

93.02 


Perct. 

0.36 

19.84 

71.53 

.90 

7.35 


Perct. 
3.19 


Acid 


34.57 


Inert 


49.74 


Alkali] 


2.99 


Peptonizing 


12.44 4.65 


9.49 


Total.... 


99.98 


99.98 


99.97 


99.98 


99.98 


99.99 


99.98 


99.98 


99.97 ' 99.99 


99.98 


99. 9S 


Number of sam- 
ples averaged 


12 


12 


12 


11 


11 


11 


9 


9 


9 


U 


11 


11 



It is interesting to note the activity of the total acid group in 
pasteurized milk of grade B, and although the average bacterial count 
was high this grade of milk more nearly represents the ordinary quality 
of milk which is pasteurized commercially than either grades A or C. 



PERCBHTAOE OF ACID FOBMINQ BACTERIA. 



As has already been shown, the acid bacteria instead of being 
destroyed by pasteurization for 30 minutes at 62.S° C. (145° F.) are 
actually increased in their percentage of the total bactma. The 
laige percentage of the 
acid group which survive 
the process are shown in 
the frequency curve in 
£gure 14. The number 
of samples were plotted 
as ordinates and the per- 
centage of the acid-form- 
ing bacteria as abscissee, 
the ranges in percent- 
ages from 0-1, 1-10, 
10-20, etc., being taken 
as points. Thirty-nine 
samples of raw and 42 of 
pasteurized milk were ex- ^ 
amined. The samples of ■" 

milk were pasteurized for 
30 minutes at 62.8° C. 

(145°F.). Itwilibeseen "^w^rd^KTmin^lbymniusmUkrwctior 

from the figure that with otincobaaoD, 

the raw milk the peak of the curve is at 1-10, while one peak of the 

curve of pasteurized milk is at 10-20 and another at 50-60. In other 





j 


\ 




















/ 


\ 


















». 


/ 


\ 


















„ 


/ 




\ 


















/ 


/ 


V 


.,^_ 






&^ 










/- 


/ 


\ 








\ 


Utt- 


















X 




^] 





r-^_^ 






" 








* A.-. 


*> ^ 




■^ eo 




•to io 


■Oo ao^oa 



w and pasteurltnl mlLk. 

words, the majority of the samples of raw milk contained from 1 to 10 
per cent of bacteria of the acid group. The number of samples con- 
677W— BiiU.161— 13 5 



84 



BACTERIA WHICH SURVIVB PASTEURIZATION. 



taining higher percentages gradually diminished until no sample 
contained over 80 per cent. Among the samples of the pasteurized 
milk, it may be seen from the curve that the majority of them 
contained from 10 to 60 per cent of the acid group and some samples 
as high as 90 per cent. 



COMPARISON OF THE PEBCENTAOE OF PEPTONIZING BACTERIA 

IN BAW AND PASTET7BIZED MILK. 

In the same manner 39 samples of raw milk and 42 samples of 
milk pasteurized for 30 minutes at 62.8° C. (145° F.) have been grouped 
according to the percentage of peptonizing bacteria which they con- 
tained. A comparison of the frequency curves in figure 15 shows 
that the pasteurized milk contained a lower percentage of the pepton- 
izing group than did, the raw milk. A large number of samples of 
pasteurized milk contained between and 1 per cent of peptonizing 

bacteria, while only one 
sample of raw milk con- 
tained that low percent- 
age. The same number 
of samples of both raw 
and pasteurized milk 
contained from 1 to 10 
per cent. It will also 
be seen from the curve 
that a few samples of 
fic^ ce9^ cr ficprmttziMs aACTiERM both raw and pasteur- 

FIG. 16.— Comparison of the peroeDtage of fhe peptonldng bacteria ized milk Contained 

Iii«wandpast«ui«dmflk. j^j^^^. ^^^ 1 tO 10 pCT 

cent of the peptonizing group. However, in a comparison of the 
raw and pasteurized milk it was found that a larger number of 
samples of raw milk contained the high percentages of peptonizers. 

AVEBAOE PEBCENTAGES OF THE BACTEBIAL GBOUPS OF BAW 

MH^K WHICH SUB VIVE PASTETJBIZATION. 

The effect of pasteurization upon the bacteria in milk may be 
shown by a determination of the percentage of the bacterial groups of 
raw milk which are found after heating. This percentage was 
obtained by subtracting the percentage reduction by pasteurization 
of the various groups from 1.00 per cent. The samples of raw and 
pasteurized milk were plated on infusion and casein agar and the 
percentage reduction of the various groups determined by the milk 
tube method. Table 15 shows the averaged results from infusion 
and casein agar plates, using three grades of milk for examination. 




"»-/ 



EFFECT OF PASTEUBIZATION ON NUMBBB OF BACTERIA. 



35 



It may be seen that a greater percentage of the acid group of bacteria 
in the raw milk remained after heating than any of the other groups. 
As a ride a smaller percentage of the peptonizing group survived 
than either of the other groups. In general the result when casein 
agar was used was higher, although the reason is not apparent. 

Table 15. — At^erage percentages of the bacterial groups of raw milk which survive 

pasteuruation by the ** holder" process. 



Pasteurization temper- 
ature. 



Media. 



Bacterial groups. 



Add. 



Inert. 



AlkaU. 



Pepton- 
izing. 



Qrade A, 62.8* C (145* F.). . 
Grade A, 7U*C.(ieO* F.).. 
Grade B, 62.8* C. (145* F.). . 
Grade C, 62.8*0. (145* F.). . 



fusion agar 
[Casein agar.. 
>nagar. 
[Casein agar. . , 
Ion agar 
[Casein agar., 
[nf usion agar 
[Casein agar.. 



1.27 
4.26 
1.71 
2.34 
6.98 
6.50 
4.56 
13.09 



asz 

.31 
.12 

1.48 
2.06 
1.59 
4.49 



ao5 

1.55 

.10 



L27 

2.05 

.19 

1.13 



0.06 
.08 
.01 
.09 

1.86 
.51 

1.24 

1.26 



THE EFFECT OF PASTEUBIZATION ON THE NUMBER OF BACTEBIA 

OF DIFFEBENT GBOUPS IN MTLE. 

In order to show the effect of pasteurization on the numbers of 
the bacteria of different groups, Table 16 has been arranged. This 
shows the calculated number of bacteria in each group determined 
from the average total counts on infusion agar and the group per- 
centages as shown by the milk-tube method. To illustrate this fur- 
ther take the samples from dairy A^ as shown in Table 16. The 
bacterial count of 12 samples of raw milk averaged was 21;100. 
The averaged group percentages of the 12 samples was 33.85 per 
cent of the acid-coagulating group, 6.85 per cent of the acid group, 
and so on. The acid-coagulating group contained on an average 
33.85 per cent of the average total count, or approximately 7,160 
bacteria per cubic centimeter. The other bacterial numbers were 
calculated in the same way. 



36 



BACTEBIA WHICH SUBVIVB PASTBUBIZATION. 



Tablb 16. — CompariMn of the number of baeUria of different groups in milk b^ore and 

after poMteurization. 



Average total count per cubic centimeter. 



Raw milk, 21,100. Average of 12 samples. Dairy A 



Pasteurized milk, 62.8* C. (145* T.), 30 minutes, 430. 
Average of 11 samptes. Dairy A 



Raw mUk, 2,840,000. Average of 17 samples. 
Dairies B and C 



Pasteurised milk, 62.8* C. (145* F.), 30 minutes, 
11,700. Average of 20 samjHes. Dairies 13 and ( '. . . 



Raw milk, 22,800,000. Average of 10 samples. 
Dairy D 



Pasteurized mflk, 62.8* C. (145* F.), 30 minutes, 
83,000. Average of 12 samples. Dairy D 



Average 
group 
per- 
centage. 



33.86 

6.85 

43.13 

3.33 

12.81 

11.85 

61.25 

22.06 

.36 

4.47 

12.96 

9.74 

43.51 

19.66 

14.10 

31.80 

34.87 

24.00 

5.63 

3.50 

36.17 

10.71 

29.31 

6.47 

17.31 

17.91 

61.87 

9.06 

9.77 

1.39 



Group. 



Acid-ooagulsting. 

Acid 

Inert 

Alkali 

Peptonizins 

Acid-coagumting. 

Acid 

Inert 

AlkaU. 

Peptonizing 

Acid-coaguiating , 

Acid 

Inert 

AlkalL 

Peptonislnff 

Acid-coagulating 

Acid 

Inert. 

Alkali 

Peptoniztne 

Acld-coaguuting 

Acid 

Inert. 

AlkalL 

Peptonizing 

Acid-ooagulating 

Acid 

Inert 

Alkali 

Peptonizing 



Calculated 
number of 
each group 
per cubic 
centimeter. 



7.160 

1.450 

9,120 

705 

2,700 

50 

267 

02 

2 

19 

368,800 

376,700 

1,236,000 

568,000 

400,000 

8,760 

4,110 

2,830 

660 

420 

8,300,000 

2,450,000 

6,700,000 

1,480,000 

3,900,000 

14.900 

51,500 

7.500 

8,130 

1.150 



The most striking features of the table is the high number of acid- 
forming bacteria in proportion to the low number of peptonizers in 
the pasteurized milk and the marked difference in the numbers of 
peptonizing bacteria before and after pasteurization. The milk from 
dairy A was exceptionally good, the average total count of the raw 
milk being 21,100 and after pasteurization for 30 minutes at 
62.8^ C. (145° F.) only 420 per cubic centimeter. The peptonizers 
were reduced from 2,700 to 19 per cubic centimeter. 

The milk from dairies B and C was of poorer quality, the average 
count of the raw milk being 2,840,000. After pasteurization the 
count was 1 1 ,700. The peptonizers were reduced by the process from 
400,000 to 420 per cubic centimeter. In the last part of the table the 
results of the examination of poor milk is shown. The average count 
was 22,800,000 bacteria per cubic centimeter before and 83,000 after 
pasteurization for 30 minutes at 62.8° C. (145° F.). The raw milk 
contained an average of 3,900,000 peptonizers per cubic centimeter 
and after pasteurization only 1,150 per cubic centimeter. Throiighr 
out the whole series may be noticed the low number of alkali-forming 
bacteria in the pasteurized milk in proportion to those in the raw milk. 
After a comparison is made of the kinds of bacteria in the raw milk 



BACTEBIAL DEVELOPMENT IN MILK. 37 

from dairies B and C and in the extremely poor milk from dairy D with 
the same milk after pastemization there should be no question as to 
the beneficial effect of the process. 

THE BACTERIAL DEVELOPMENT IN MH^K PASTEX7BIZED IN THE 
LABOR ATOEY AND HELD AT DIFFEBENT TEMPER ATTJKES. 

After having determined the groups of bacteria which survived 
pasteurization, their subsequent development was traced in a few 
samples of milk. 

The changes in the bacterial flora of milk pasteurized for 30 minutes 
at 62.8® C. (145° F.) during storage at different temperatures has been 
studied in a poor, medium, and good grade of milk. One sample of 
each grade of milk was divided and each part pasteurized in a sterile 
flask. After pasteurization each sample was held in the ice box at 
approximately 7.23° C. (45° F.) for 18 hours; then one flask was held 
at room temperature, the other was kept in the ice box. After pas- 
teimzation and on each successive day each sample was plated to 
determine the number of bacteria which were then differentiated by 
the milk-tube method. On account of the great amount of work 
involved and time consumed in determining the bacterial flora by the 
milk-tube method only one sample of each grade was studied. 



38 



BACTERIA WHICH SUBVIVE PASTEUBIZATION. 



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BACTERIAL DEVELOPMENT IN MILK, 39 

The daily bacterial group percentages are shown in Table 17. The 
room temperature varied from 21.1''-23.9° C. (70°-75°F.) whilethe 
temperature of the ice box ranged from 8°-10° C. (46.4°-50°F.). The 
bacterial group percentages in each raw milk are shown followed by 
the "0" day determination which gives the group porcentages imme- 
diately after pasteurization. Sample G represented a poor quality of 
milk, H a milk of medium quaUty, such as is usually commercially 
pasteurized, and sample K an excellent grade of milk containing only 
a few thousand bacteria per cubic centimeter. The samples of milk 



i 



I 



„ , , - . I 

Fio. 16.— Dally changte In ' « ~ 

the baetflritl group reli^ 

Uoiuln put«]tl»d milk. Flo. 17.— DsUrchsngn In tha bacterial group relations In pastnuiiud 
Sample O beld at room milk. Sample O heid In the ice box. 

tanponitiirB. 

were pasteurized and held so as to prevent any possible reinfection. 
In order to show the changes in the groups more plainly, the results 
from Table 17 have been plotted. Figure 16 shows the changes in 
the bacterial flora of sample G held at room temperature. This sam- 
ple showed a rennet curd oo the third day. Wtile there was a little 
acid development during the first three days, a rapid increase 
occurred from the third to the fourth day. From the figure it may be 
seen that there was a rapid increase in the percentage of the pepto- 
nizing group from 4.75 per cent on "0" day to 20 per cent after one 



40 BACTEEIA WHICH 8UBVIVE PASTEUEIZATION. 

day, then to 80,95 per cent after two dajrs, followed by a drop to 20.79 
per cent the third day. Corresponding to the increase in the propor- 
tion of the peptonisdng group tJiere was a decrease in the acid group 
followed by an increase on the third day. The acid group comprised 
86.71 per cent of the bacteria at first, then dropped to 67.69 per cent 
after one day, then to 9.52 on the secohd day, then increased 53.96 
per cent. The percentage of the alkali group throughout was low. 
As the plot shows, there was a rapid increase in the peptonizing bac- 
teria which produced a rennet curd on the third day. Up to that 
time the development of the acid-forming 
bacteria was slow, and while there was 
some development of acid, apparently not 
enough was formed to check the develop- 
ment of the peptonizing group. To sum- 
marize, it may be said that in sample G, 
hold at room temperature, there was a 
rapid growth of peptonizing oi^anisms 
which produced a rennet curd, followed by 
acid development produced by the growth 
of the acid-forming bacteria. 

The other portion of sample G was held 

in the ice box. Figure 17 shows the ro- 

Bults graphically. It may be seen thft 

there was only a slight acid development 

during the 13 days' holding period. The 

most striking point is the restriction of the 

development of the peptonizing group by 

the low temperature at which the sample 

was held. A comparison of the plot of the 

peptonizing group in figures 16 and 17 

shows this point plainly. There was a 

< slow bacterial development during the first 

six days as shown by the total counts. 

During that time the percentage of the acid 

' group was high. From the seventh to the 

"SiTri'ltSSS^ nbth day the per cent of the «id group 

BampiBHhBidBtroomtmiperaiura. ^vas low, with a Corresponding increase in 

the alkali and mert groups. From the ninth day the percentage of 

the acid group began to increase and the acidity also uacreased. 

The bacterial groups were not studied after the thirteenth day, but 

the sample was held and acidity was determined daily. It was 

found that the milk eventually soured. After eight days an old 

taste developed which would prevent its consumption as a food. 

The changes in the bacterial flora of a better grade of milk repro- 
sented by sample H were much different when the milk was held at 
room temperature. As may be seen from figure 18 the milk soured 
with a constantly increasing percentage of the acid group and decrease 



BACTEBIAL DEVELOPMENT IN MILK. 41 

in the other group percentages. The percentage of the acid group 
increased from 58.69 after pasteurization to 91.71 after six days. 




-/e J9 J9 — '^ ys .go . 



•^ 



Pia. IS.— DaUjr cbacgBs In Ihe bacterial group relslions la pasleuriied milk. Bunple n held In In boi. 

The percentage of the peptonizing group was 0.54 immediately after 

beating and none appeared in the plates in the later examinations. 

The changes in the groups of the other portion of sample H held in 

the ice box are shown in figure 19. The development of the alkali 



42 BACTEBIA WHICH BOBVIVE PASTEURIZATION. 

group after four days is plainly shown. With the increase in the per- 
centage of the alkali group there was a corresponding decrease in the 
acid group. After 10 days the percentage of the alkali group began 
to decrease and the acid group to increase. The percentage of the 
peptonizing group was low tliix)ugh the whole period. The acidity 
did not change until the twelfth day. After 11 days the milk had an 
old taste and would not be used. 

' The changes in the bacterial groups in the best grade of milk repre- 
sented by sample K were different from the others when the milk was 



Mil 



FiO. 20.— Dally changes 
Um bacUrlal group >bI 
tlona Id pastourlxed mi] 



I -^M « M . Ml I || , II 

Flo. 21.— Dail]- cliBQe« In Ihs tncUiial group relatione In pasHniiiaJ 
[emperBtUTB. "■Ul'. Sample K held In Uis Ice boi. 

hold at room temperature. After six days the milk was putrid and 
digested, but had not coagulated. As may be seen from figure 20, 
there was no acid formed. On the second day the peptonizing bac- 
teria began to increase rapidly, and on the fourth day only organisms 
of the peptonizing group were found. The acid group gradually 
decreased until the second day, after which none appearotl on the 
plates. The cxtrDnii! changes in the group percentages were due to 
the low number of bacteria in the milk. WTien only a few colonies 
appeared on a plate the determination of the groups was of course, 



QUALITATIVE STUDY OF GROUPS. 43 

much less accurate than when 100 or more colonies are studied by the 
milk-tube method. 

The restraining efiFect of low temperatures on the development of 
the peptonizing group is again plainly shown in figure 21 ^ which 
represents the bacterial group changes in the other portion of sample 
K held in the ice box. No peptonizing bacteria were found on the 
plates throughout the whole series and none of the alkali group 
appeared until the twelfth day. The acid group predominated 
throughout with considerable fluctuation due to inaccuracy on account 
of low bacterial numbers. The total counts were very low until the 
eleventh day, after which there was a rapid increase. After 17 days 
an old taste was noticed and at that time the acidity began to increase 
slowly. 

These results are shown merely to indicate the possible changes 
which may take place in nulk pasteurized in sealed bottles. It is 
clear that there is a delicate balance between the various bacterial 
groups which may be influenced by conditions of temperature and 
time so that various effects may be produced. These results can not 
be applied to commercial problems, since in laboratory experiments 
it is impossible to duplicate commercial conditions. In order to 
determine the changes in milk commercially pasteurized in sealed 
bottles a study must be carried on only under commercial conditions. 

QUALITATIVE STUDY OF THB OBOUPS OF BACTEBIA WHICH 

SUBVXVE PASTBUBIZATION. 

During the determination of the percentage of the bacterial groups 
cultures were selected for further study. These were selected from 
milk pasteurized at 62.8° C. (145° F.) for 30 minutes. The cultures 
were purified by plating, then examined microscopically and for their 
cultural reactions. In the tables of the Appendix the complete reac- 
tions are shown. 

THE ACID-FORMING GROUP OF BACTERIA. 

The acid-forming group of bacteria have been grouped arbitrarily 
as shown in figure 22. One hundred and thirty- two cultures were 
examined and were divided into four classes. The first class comprised 
89.39 per cent of the cultures. TTie reactions of this class are shown in 
figure 22. All the organisms were cocci which produced no liquefac- 
tion of gelatin. The Gram stain was either positive or negative, 
nitrate was not reduced, and some formed pigment while others did 
not. Dextrose, galactose, and lactose were fermented. Some cul- 
tures fermented saccharose. Of those that fermented saccharose, the 
ability to ferment raffinose, starch, inulin, mannite, glycerin, and 
salicin varied as may be seen. The same may be said regarding those 
cultures which did not ferment saccharose. The second class was made 



44 



BACTEBIA WHICH SUBTITE PASTEUBIZATION. 



up of nonliquefying bacilli, Gram positive, nitrate reduction positive or 
negative, and all produced pigment. Dextrose, galactose, lactose, 
and saccharose were fermented ; raffinose positive or n^ative, starch 
positive or n^ative, inulin not fermented, mannite positive or n^^ 
tive, glycerin not fermented, and salicin positive or negative. This 
class comprised 3.03 per cent of the acid group cultures, llie third 



TOTM. MfMee» /St. 




ig group ot bulaila. 



class contained 6.81 per cent of the cultures and was made up of 
hqucfying cocci, Gram positive, nitrate reduction positive or negative, 
and none produced pigment. The acid production was as follows; 
Dextrose, galactose, lactose, and saccharose positive ; raffinose, inulin, 
and starch negative; mannite and glycerin positive or negative; and 
salicin negative. 

One culture formed the fourth class. It was a liquefying Gram 
positive bacillus which reduced nitrates and formed no pigment. 



QUALITATIVE STUDY OF GROUPS. 



45 



Acid was formed in dextrose, lactose, saccharose, and glycerin. The 
complete reactions of each variety of bacteria are shown in Table I 
of the Appendix. 

In general it may be said that the majority of the acid group which 
survived pasteurization at 62.8° C. (145** F.) were nonliquefying 
cocci which varied widely m their abUity to ferment the various 
sugars. A small percentage of acid-forming bacilli also survived, 
together with a few acid-liquefying bacteria. 




3/ cut 



COCCA 



± 
PfSMEfrr 

± 







THE INERT GROUP OF BACTERIA. 

The study of the inert group has not been given much attention. 
All bacteria which produced no change in litmus milk after 14 days' 
incubation at 30° C. 

(86° F.) were classed TOTj^L M//^S£^ ^^ 

according to the milk- 
tube method as inert 
organisms. The group 
would therefore contain 
not only those bacteria 
which did not produce 
any change in milk un- 
der any condition, but 
also any organisms 
which did not happen 
to grow in the milk 
tubes and those which 
might produce a change 
in milk after the 14 



a/9c/ci,/. 



± 

p/sMSj/r 

± 



AlfO Uf 1 







] 



Fig. 23.— The alkali-fonniDg group of bacteria. 



days' incubation 
period. 

In a number of sam- 
ples agar streak cul- 
tures were made from 
the litmus milk tubes which showed no change. Sometimes none of the 
agar cultures showed growth ; in other cases approximately 2 per cent , 5 
per cent, 25 per cent, 80 per cent, and occasionally 100 per cent showed 
growth on agar streaks. When those agar cultures were reinoculated 
into litmus milk, some would not produce any reaction and others a 
slight alkaline reaction after long incubation. Often a yellow color 
was noticed in the litmus milk culture which indicated an inert yellow 
pigment-forming organism. 

THE ALKALI-FORMING GROUP OF BACTERIA. 

The alkali-forming bacteria constitute a group which has been given 
but Uttle study in connection with the bacterial flora of milk. In 



46 



BACTERIA WHICH SURVIVE PASTEURIZATION. 



the differentiation of the various groups on litmus lactose gelatin 
plates, organisms of this group would be entirely missed, but they 
are easily found by the milk-tube method. Forty-three of these 
organisms isolated from pasteurized milk have been studied and 
grouped arbitrarily, as shown in figure 23. The alkali group was 
made up of 72.09 per cent of cocci and 27.90 per cent of bacillL 



707>9JL A/OAfSE/^ SO 







CZASS /v. 



cqcc/ 

CAS£/*f OfS£S7ieO 
GRAM 



9¥» 9% 

COCC/ SB^C/LU 

Sei A7li¥ 

± 



»am09tj scmnmr 



Af/TRAT^^DUCeO 



coca « e^au./ 









fGfjovr 




Flo. 24.— The peptonklDg group of bacteria. 

It is not necessary to go into minute details regarding these oi^anisms, 
for their characteristics are plainly shown in the figure. They did 
not liquefy gelatin, and produced a strong alkaline Reaction in litmus 
milk. No acid was produced in the sugars, starches, alcohols, or in 
the glucosid used in the investigation, but an alkaline reaction was 
often found. In litmus milk often enough alkali was produced to 



QUAUTATIVE STUDY OF GROUPS, 47 

dissolve the casein. That will always happen if the period of incu- 
bation is long enough. The complete characteristics are shown in 
the Appendix in Table II. A more extended study of the alkaU group 
is under way in the research laboratories of this division. 

THE PEPTONIZING GROUP OF BACTERIA. 

The peptonizing bacteria include only those which peptonize the 
casein of milk. Fifty of this type of organisms were studied, and 
their characteristics are shown fully in the Appendix in Table III. 
They were divided arbitrarily into four classes, as shown in figure 24. 
It may be seen that the bacteria of classes 1 and 2 did not liquefy 
gelatin during 30 days' incubation, but did peptonize casein. The 
peptonization of casein was determined by streak cultures on casein 
agar slopes by the following method : 

After 14 days' incubation the slopes were flowed with N/lOth lactic 
acid. If. no peptonization has taken place the casein will be precipi- 
tated by the acid. If peptonization has gone on, then the casein agar 
will remain clear, showing that the casein has been dissolved. The 
use of casein agar for the determination of peptonizing bacteria in 
milk is ifuUy described in another publication ^ of this departmfent. 
It will be seen from figure 24 that classes 1 and 2 comprise both cocci 
and bacilli, some of which did not ferment sugars, while others pro- 
duced acid. Classes 3 and 4 is made up of bacteria which liquefy 
gelatin and may or may not ferment the sugars. It is interesting to 
note that out of 225 cultures of bacteria studied only 3, or 1.35 per 
cent, formed spores. Those 3 cultures were found among the 50 
peptonizing organisms making only 6 per cent of the peptonizing 
spore-forming organisms. 

THE GAS-FORMING BACTERIA. 

During the study of 225 cultures selected at random from the 
samples of pasteurized milk only two organisms were found which 
produced gas in milk. One of the gas-forming bacteria, culture 417, 
was a Gram negative short bacillus which peptonized casein but did 
not hquefy gelatin. It produced gas in lactose broth and acid in 
dextrose, saccharose, raffinose, starch, and sahcin broths. No acid 
was formed in lactose, galactose, mannite, glycerin, or inuUn broths. 
Nitrate solution was reduced. Gas was produced in htmus milk 
and the milk was curdled with some peptonization. It is evident 
that this bacillus did not belong to the colon-aerogenes group. 

The other organism is an entirely new type so far as known. This 
culture known as Z produced gas in milk but not in lactose broth. 

I Ayers, S. Henry. Casein media adapted to determining bacteria In milk. United States Department 
of Agrloulture, Boreaa of Animal Industry, Twenty-eighth Annual Report, 1911 (In press). 



48 



BACTEBIA WHICH SUBVIVE PASTEUKIZATION. 



^ 



Culture Z was a long motile Gram negative bacillus. In a hanging 
drop preparation a few cells had an enlargement at one end which 
probably represented spores, although it was impossible to demon- 
strate their presence by staining reactions. Their survival of an 
exposure to a temperature of 93.3° C. (200° F.) for 30 minutes seemed 
to affirm the presence of spores. It grew slowly on agar streaks and 
produced a slimy growth. A 2 days' old culture often showed 
extremely long types of organisms. Acid was produced in dextrose, 
galactose, and saUcin broths, but not in saccharose, mannite, gly- 
cerin, raffinose, inuhn, or starch broths. When these broths were 
used for gas production it was found in one experiment that culture 

iZ produced gas in raffinose, mannite, and starch 
broths after 14 days' incubation at 30° C. (86° F.), 
but none in any of the other broths. This ex- 
periment was repeated and no gas was found in 
any of the broths. Nitrate solution was reduced 
and gelatin was not liquefied after 30 days' incuba- 
tion at 18° C. (64.4° F.). This culture produced 
acid and gas in milk and coagulated it after 14 
days. The ability to produce gas in mUk through 
a long period is one of the striking characteristics 
of this organism. In order to determine how 
long culture Z would continue to produce gas in 
milk, a 25 cubic centimeter burette was inverted 
and inserted through a rubber cork into an Erlen- 
meyer flask containing 200 cubic centimeters of 
mUk, as shown in figure 25. By opening the stop- 
cock of the burette the milk could be drawn to 
the top and the tube filled. After sterilizing, the 
milk was inoculated with culture Z and incubated 

FIG. 25.-Apparatiis for the ^^ 3^° C. (86° F.). The gas produccd was re- 
determination of gas pro- corded daily and when the burette was filled 
ductioniumiik. ^j^j^ ^^ ^j^^ stopcock was opened and the 

tube was again filled with milk. In that way it was possible 
to record gas production from milk over an indefinite period. 
As may be seen from figure 26, this organism was able to pro- 
duce gas through a period of 46 days. The fermentation began 
after 24 hours' incubation when from 3 to 4 cubic centimeters 
of gas was formed daily until the fourteenth day, when the milk 
was curdled. At that time the daily gas production increased and 
was sometimes as high as 15 cubic centimeters. The increased 
gas production continued until the thirty-first day when it was 
reduced to approximately 4 cubic centimeters per day. The gas 
produced was hydrogen and carbon dioxide. The ability of culture 




—3-:^^^^^ >9KMr 



QUALITATIVE STUDY OF GROUPS. 



49 



Z to produce gas in milk continuously for a long period, together 
with the fact that while gas was formed in milk lactose in broth was 
not fermented, differentiates this organism from the ordinary types 
of gas formers. A more extended study of this type of organism is 
under way in the research laboratories of this division. 

The survival of pasteurization by gas-forming bacteria is of con- 
siderable importance, since it has been suggested to make the pres- 
ence of the colon group an indication of recontamination of pasteur- 



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